I am confused as to how/what taxes should be paid by me.

I came to the US in January 2002, and I been a student ever since that day.

In 2007 (I first filed as a resident for the tax year 2007), I was doing a part-time CPT internship at a bank I asked them to charge me for FICA because I believed I have stayed 5 years now, and I need to pay these taxes? Was I correct?

The college said they will not charge me FICA because I was a full-time student.

Then I did another full time CPT May - June 2007 and I paid FICA as well.

But in 2008, I started my current full-time job under OPT and got my H1-B for October 2008. I realized today that I was not charged FICA up to now. This was the same company I did an internship with and who charged me for FICA before, so I though all this time they were charging me for FICA, but they have not.

I believe starting this month they will charge FICA to my paycheck because I am on H1B now.

My questions are:
1. Do I need to file refunds for the FICA I paid as a student (eventhough I was here for 5 years) during my CPTs?

2. What would happen to the last 8 months where the company did not charge me FICA because I was on OPT? Would I need to pay that?

Thanks in advance for all your help. I know this topic might have been answered before but I couldn't find a clear answer to my situation.

1. After 5-years on F1, you are not exempt from residency. You will not get FICA taxes back.
2. If IRS will question anyone, it is your company. You are not responsible. You are responsible only if you made a wrong statement about your F1 visa.
It is better that you talk to HR department of your employer so they collect back FICA taxes from you.
3. You filed correct return in 2007-- resident return.
File resident tax return in 2008.

Note that a non-resident tax return was required for 2006; last year for that return.

The reason that the university did not charge FICA has NOTHING to do with your residency status. ALL students (domestic or international) who work in jobs on university grounds while a student at that university are exempt from FICA taxes.

The rest of MukatA's advice is solid!

So if I am understanding this correctly

You said "Note that a non-resident tax return was required for 2006; last year for that return.", I filed as a resident for the first time 2008 (for the tax year 2007). In 2007 (for the tax year 2006) I filed a non-resident. So I have filed correctly , right? If not please correct me.

If you filed as a non-resident (Form 1040NR or 1040NR-EZ) in 2006 and a normal (Form 1040/1040A/1040EZ) in 2007. Then you filed correctly.