Can i recover the taxes i overpaid last year due to not adjusting cost basis for sell to cover RSUs?

[TomYoung]

Yes.  You'll need to file an amended income tax return.  You'll go back to the "Stocks, Mutual Funds, Bonds, Other" interview and correct that particular trade to reflect the correct basis.  A typical "same day" sale results in a small loss due to selling commissions and fees.

This FAQ

http://turbotax.intuit.com/support/iq/Amend-a-Return/How-to-Amend--Change-or-Correct--a-Return-You-A...

will get you started on the amending process.

Tom Young