Bad Service MTN

I pay my account by debit order but with this pandemic there is sometimes not money in my account, the debit order did not went through on the last day of the month but on the first, the bank rejected the payment, I made a payment on the third, but the bank did not allow me to enter the whole account number or cellphone number only the last eight digits of the account number. I phoned a service champion to explain the situation and send her the proof of payment, my service was disconnected and they have tried many times to put through a debit order that incur fees. Please look at your account and allocate the payment!!!!!!!!!!