First of all, the transaction in your place can be regarded as a deal, because you met the household whose bank loan approval letter has been approved, and now the house belongs to you.

Secondly, the remaining house payment is paid by the bank to the landlord. Even if it is written in your contract, it is useless. You can't restrict the third party from making promises.

Finally, the landlord said it was unreasonable not to sell now. In the end, if you go to court, you will win.

Now the solution, you ask the intermediary first, what is the basis of bank lending? See mortgage registration, that is, when the mortgage registration can be completed. It does not rule out the possibility that some banks have tight lending quotas and slow lending. So, in the end, you must negotiate with the bank. If the owner pesters you again, take him to your loan bank.

There must be an agreement in your contract that the house you bought with a loan must be paid out by the bank.

I hope it helps!