Wait a little longer. Despite being told you won't get a W-2, you may still get one.
If I understand this correctly: you only received $8K, but paid back $14K? And the paystubs show the withholding?
If you don't get a W-2, you'll prepare a substitute W-2, in TurboTax, as part of your tax return, to get the federal income tax withholding refunded. Prior to doing that, you're supposed to make some effort to get a W-2 from your employer, including reporting them to the IRS.
You'll have to file a claim for the FICA refund using Form 843, which is not supported, by TT and is not part of your income tax return. Again, prior to doing that, you're supposed to ask your employer to refund it to you (they request a refund from SSA).
