Horrible Service

On the 18th March I contacted MBD for my Vodacom account, I was told that I have a discount on the settlement amount. Gontse Tongwane and her line Manager Martin Magosi sent me the settlement details with the discounted amount and I was very clear That there payment will be made on the 19 March by EFT. Payment was made as per agreed, POP sent to Martin and he confirmed to have received and advised that he will monitor for payment to reflect then send me my Paid up later. To my surprise I am getting emails from MBD that I have an outstanding balance and I have forwarded this to Martin and Gontse. They have since ignored by emails from the 22nd March. I called again and the agent I spoke to was not much help as she told me the payment was made later and that is not there case. I will not pay this outstanding balance, I have proof on emails that there settlement figure was given to me by the above mentioned individuals. I need this to be sorted as soon as possible. Ref ***