26QB error

Dear Sir, I had bought a house in Mumbai for 77 lacs & paid 1% tds of 77,0000 on traces in March 2015. However the reflection in assessment year 2015-16 shows the transaction in part A2 and I am seen as the seller of the property and seller is seen as buyer & hence I am not able to generate form 16B. The sellers CA was trying all these years to change the same with sellers AO. I was being told that it has been done but now in March 18 the seller has approached me that it still not done. Then after some research on internet I came to know about changing the same online through change request in 26QB on traces which is being initiated yesterday by sellers CA. My question is 1. Is the last date to avail this claim 31st March 2018? 2. There were 2 buyers and 2 sellers (property in name of husband and wife for both buyer and seller) but I have paid the entire tax amount of 77,000 from first buyer i.e. in my name to 1st sellers name in 1 challan? Will this have any future implication? 3. If it is not done by 31st March what could be second option to do this. 4. Can I revise my IT for assessment year 15-16 take refund (please confirm under which head) of the amount and then again pay to seller? Will there be any late fee? Regards Abhishek Rane