Why would USMC recruiters avoid a candidate?

They didn't need the contract and they were stringing you until the next quota period.

Policies change in recruiting month to month. Maybe they weren't accepting prior service at the time. Maybe the recruiter was in school. Or maybe just lazy.

It's your career and nobody is gonna care more about it than you. If they don't answer your calls just goto the office.

On behalf of the Corps, I would like to appologize to you, for apparently finding the one idiot on recruiting duty.
Not contacting you, not keeping those lines of communication open to you, was a rotten thing to do, and totally uncalled for.
I was a 're-tred' as well, entering into the Corps after the Army, and yes, there is more paperwork, and yes, it is all round, more work, but damn! We 're-treds' are halfway there... we already know the finer points of weaponry, we know all sorts of things that they don't have to waste time re-teaching us, and we usually end up at the top of the class, because most of us can focus on the newer things, instead of how to make a hospital corner, or just how to clean a rifle!
My unmet friend, if you still want this, and I should warn you, its hard going thru Boot older than 99% of your group, so you have to want it more than you've ever wanted anything else, for two reasons... the first being that they will see it as their duty to 'clean the Army crap out" and secondly, you are going to be pointed out in every situation as a Blessing or a Lesson... so be prepared!
Again, on behalf of MY Marine Corps, I offer profound apologies for the run-around you endured.

As s former recruiter. The one you were working with was weak. Because your a prior service it may or may not involve more paperwork. Once you were qualified you should of been in. USAREC eats its own. My 1SG would of had my ass if I lost a PS applicant.

As a former Marine Corps recruiter I can tell you there's a couple reasons why the recruiter not call you back. The first is that because you already served in the Coast Guard, you were considered prior service and are much harder to place in the Marine Corps as they very rarely have spots available to except prior service. When they do it's typically prior Marines first then all others. This is mainly because you would still have to complete Marine Corps boot Camp even though you had already completed Coast Guard Boot Camp. Also, secondly the Marine Corps doesn't like to re-tread service members with no Marine Corps experience coming into the Fleet Marine Force for the first time possibly holding a higher rank than those experienced Marines in a junior leadership position.

There are a couple reasons. Recruiters maybe "sandbagging". That means that the recruiter had made mission for the month and will hold on to a prospect until he needs it. If not that, the mission the recruiter has may have changed, or the number of prior-service recruits that the recruiter of the station can put in may have changed.
One thing that we don't want to think of but i very true, Once you are in the service, and you get out, it is NOT the priority of the military to bring you back in. Prior service that are still in the Individual Ready Reserve are still in the service. So, for prior service, during a drawdown, you were lucky to get back in anyplace. this is why, when I was the retention NCO, I made sure to remind the Soldiers I talked to that they needed to be double sure before they got out. you might not be able to get back in.

Same thing happened to me. I was in the NJ national guard on 9/11/01, and I wanted to go back on active duty, but in the Marines. The recruiter said he could do it, explained I would be an E2 again and go to bootcamp, I already knew that and was ready. He literally disappeared. The office was closed and I had to drive to the other office in red bank. The senior recruiter was not interested in doing the paperwork, tried to pawn me off on the Air Force recruiter next door. Well, I wasn't trying to go down the food chain, so I went back in the regular army. A week before I shipped out, the NEW marine recruiter called me and wanted to get me in. I said too late. Guess it was t meant to be.

It seems harder for prior service to join, but they should be upfront about that and not leave you in the dark.

In my 12 years in USAREC, I don't remember the Marines ever taking Prior Service. We put in former Marines on occasion because they couldn't get back in the Corps and only the Army was taking prior service at the time. I am surprised they didn't tell you that up front.

SPC Sayi, I went through the a similar process a few years back. I got out of the Marine Corps in 2002. When I decided I was going to return to service I took me 10 months and 9 different recruiters before I made it back on active duty. The problem is coming in prior service is an uphill battle, and they only accept them a certain time periods. My advice is if you are looking to go on Active Duty go to an Army Recruiter. In the long run I'm glad I didn't go back to the Marine Corps. Don't get me wrong once a Marine always a Marine, but from an opportunity for advancement standpoint the Army has a much larger range of possibilities.