MTN close account

I have been EXCHANGING emails since June 13 with MTN to give me the early settlement fee for me to close my account early and the account reference to use when I pay this amount using FNB's public recipient name 'MTN Contract Account/payments'. Both references given do not work and FNB took me back to MTN to fix the error. I have sent MTN screenshots of how I am entering the details which they say is correct but I keep getting the error 'reference invalid for MTN... error code 133'. This now begins to feel like sabotage as if to not allow me to close my account because they now answer questions I did not ask on emails. Can i be assisted to close this account?