Vendor is denied to sale deed and registration

I have an sale agreement with the vendor for purchasing of plot of 200Sqm at the rate of 16075 per Sqm and i have paid 700000 (Seven Lacs rupees ) at the time of sale agreement and the remaining balance amount will be paid at the time of sale deed and it registration within 90 days from the date of sale agreement. Further i have applied sale and construction of house and i got loan sanction letter from the bank within 40 days and plot sales amount is ready for disbursement. I requested vendor to show the original document to Banker lawyer to verify the same and disburse the amount in favor of vendor and come for the sale deed and registration of the property. Vendor is not ready to accept the balance amount through account Pay and demanding the amount in cash in Black and he clearly stating that i will not registered the property until you pay the amount in cash. Now sale agreement will expires in 10th Oct 2020. In view of above you are kindly requested to advise what to do? Thanks