Refund of token amount of property

Dear All,

Appreciate you help in below matter.

We have decided to buy a resale flat in Mumbai. We identified the flat with the help of broker and understood the history of the flat from the seller.

History of the Flat:

1. Flat is jointly owned by husband and wife (the sellers)
2. Flat was originally bought by way of loan in the year 1999
3. In the year 2001 the sellers transferred the loan with other bank
4. In the 2014 the sellers mortgage the flat with another bank. Mortgage amount taken by the seller is still outstanding.

Details of the sale transaction:

1. We have agreed the total sale consideration in presence of Broker and paid 2,11,000 in cheque as a token amount.
2. We have a receipt of the said token amount paid to seller and same has been signed by both husband and wife.
3. As per the broker guidance we have drafted the MOU but seller didn’t signed the MOU. We followed up for so many times but he was not keen to sign MOU.
4. As there were multiple banks involved and given loan for the same property PLUS the mortgage on the property, we decided to go for the Legal search on the property.
5. The sellers were not ready for the legal search and did not allowed us to submit the xerox copies of the agreements and other legal documents of the flat with Legal consultant.
6. Meanwhile we asked him to set up a meeting with the cooperative society secretary and other committee members which he did.
7. Seller gave a letter to the cooperative society duly signed by the sellers stating that he intends to sell the flat to us.
8. Two months later sellers called me and informed that he did not want to sell his flat for some personal reasons and he promised me that he will return my token amount with interest.

Please guide me to recover the token amount:

1. Is there any legal remedy to recover the money if there is no MOU signed and only receipt of the token amount given?
2. Is there any time limit to file a case against him?
3. Seller is ready to pay money but taking time to repay me.
4. The broker involved is also asking the seller to honour the deal and understands that the seller is at fault

If you need any additional information please feel free to ask me I will provide the required details.

Thanks in advance gentlemen. 
Any help would be greatly appreciated.
Thanks again.