I was promoted from E-1 to E-3, never wore the pv2 insignia and never recieved E-2 pay. Is this a common occurrence?

Keep the attention of that HR Specialist, and ask him what paperwork is required to validate this. Then take that paperwork to the Pay office.

Cardinal rules:
--Take down names of everyone that told you everything about every issue. Leading with, "Some guy told me that..." will not get you far.
--Keep copies of EVERYTHING in your whole career

I would complain that I never had the opportunity to do my time as an E2 and demand that I be given the opportunity to experience that rank!

All kidding aside, I would follow the steps outlined by CSM Felipe Mendez. As expected, he nailed it right on the head

Back in 1982 the way it worked is you were an E-1 until the day after you completed Basic Training. Then you were promoted to whatever grade was promised on your enlistment document. I was given E-3 for enlisting for six years instead of four.

There are times in which Personnel Action/Promotion section are disconnected. You should check in with the promotion section first to see if you were ever paid as E-2. Check your promotion/award form located in the promotion section. If you have not being paid, have them contact Personnel action/finance to correct this error. In addition, check with finance, promotion section and personnel to see if you are going to receive the E-2 back pay once you get promoted to PFC/E-3, submit a DA Form 4187 request for back pay. There is a document that is send to your Battalion monthly (forgot the file form number) to be screen by every Battalion personnel action section, first Sergeant and Battalion CSM. They should have been able to correct this error a while back. Since promotion to E-2, E-3 and SPC/E-4 are automatically as long are approved by chain of command. When screening such document, they should have check your time in grade as E-1 and see why you have not been promoted to the next rank (in this case, E-2) and so on. There are times that individual are been paid for one rank and shows different rank on the personnel action tracking sheet. This mistakes are and should be easy to fix. Use the proper channels to get this done, if everything fails, use the open door and see your senior enlisted either, 1SG and BN CSM. Good luck.

Don't look a gift horse in the mouth. I'd say thanks, and yes it's a rare occurrence.