TDS deducted by buyer of property but seller refused to deduct TDS from sale amount

Hi,

I have bought a property in March this year and on the date of purchase the seller threw a surprise that I have to pay TDS and the full sale amount (without deducting TDS). He claims that he will not claim TDS refund and was ready to give it as affidavit. Also since a lot of time and money had already spent I could not back out last minute.  So I paid the TDS + full sale amount and bought the property. The seller (actually sellers) also gave an affidavit that they will not claim the TDS refund and will share the ITR return filed.

1. Now how do I know if sellers has claimed the refund ?
2. Will that affidavit stand in court?
3. Seller is asking for sale deed agreement. I think they need it for proof to submit to IT dept for refund claim (just my hunch), can I deny it and ask them to first show me their ITR return filed.

Please advise