Rectification of Error(after BS)

Sales return book must be Credited with same amount. (Can use payables account)

T corporation is sundry creditors aka payables, must be credited back 21500₹. Debit receivables with 12,500₹.

Credit purchase returns book with 12,500.

No wonder no one passes exams properly because of the language, look here, sales return was debited or credited was not given. These question papers will never change 

Sure, what ever way one can adjust, one can do it. The key to rectification of errors is having clarity on wrong transaction, This is a very important chapter in accounting.