Premature cancellation concern

I was quite impressed with the service and help received from Vodacom regarding early cancellation of my contract. I called the retentions team and they assisted me with a premature cancellation quotation of R8835.97 which I paid within the 14 days specified by them. I made payment on the 10th November. To my surprise, 25th November Vodacom debited an amount of R1388.26 which is more than my normal monthly debit AND was not supposed to go off because I paid the amount quoted to me on the cancellation quote so as I understand I do not owe Vodacom anything.

Vodacom has now sent me another invoice for R9027.74 which they say is outstanding and I will not pay this amount because I PAID THE AMOUNT QUOTED TO ME ON THE EARLY CANCELLATION QUOTAION. I cannot call retentions anymore as my cell number has been converted to prepaid and the *** number is only for contracts.