Settlement and debit incompetence

I am beyond tired of the incompetence at vodacom!!! I requested to settle one of my accounts with vodacom on the 13th to which i got the settlement request along with the banking details. I paid the amount as per the invoice and sent the documents through to the email as stipulated on my vodacom cancellation request. Here's what makes me upset - I never received confirmation that the account is now closed as required on the NCA act, however Vodacom only debited half of my account on my debit order.... Is it now my responsibility to contact you and rectify the mistake once again??? I tried contacting the call centre even to advise that YOUR COMPANY made a mistake however no one answers.... I don't work for Vodacom - Why must i fix your mistake??? is it now my fault you debited not only the wrong amount but also failed to close the account i requested??? CAN SOMEONE PLEASE FIX THIS??