you should have gotten w-2g's because of the amount of the winnings and withholding. those forms would n be filed by the gambling establishment with the IRS and state
if you don't have those w-2gs your going to have problems claiming the withholding because with no in for the casino entered, the IRS won't be able to match what you claim with what's on file for you.
you may want to go to the IRS website, register and then get a tax transcript to see if there was reporting. you may be able to use that info on your return if you don't have those tax forms but only if you e-file.
https://sa.www4.irs.gov/secureaccess/ui/?TYPE=33554433&REALMOID=06-00008e4d-63f6-1187-a229-7c2b0ad00...
