Poor communication and service

I went to the branch over the weekend, to find out about upgrading early, as i am due for an upgrade on 01/07/2019, but there are current offerings that i am interested in. I was told that i have to pay the commitment amount, return the slip, and they will then send it to the finance department, and they will go ahead to approve the upgrade. Yesterday i went to the Mimosa mall branch, got the commitment amount and paid it in cash at Nedbank. They sent the proof and contacted the Finance department who said that because of a prior reversal i would have to wait until the end of May so that all payments will reflect before i can upgrade, however all the amounts owed have been paid in full and there was R598.00 debited on 15/04, as well as R1841.36 on 29/04, thus there are no amounts in arrears, and all arrangements and commitments have been met. I have now also paid the additional commitment amount of R705, as requested, but am being refused to upgrade. Why was the finance department not contacted prior to giving me the commitment amount and me already making the cash deposit at Nedbank, to avoid this delay? Why doe i have to wait until end of may? and what is going to happen with the extra funds i deposited? if you are not willing to assist me with the upgrade, then i expected that money to be paid back to me, and not credited on my bill, as the intent for the additional funds was for an upgrade. I know that if i wait until end of may, they are going to have another excuse, and the funds would have already been allocated to my account despite my wishes, this exact same thing happened with my wife as well, and i find it very unprofessional that we are not fulle informed prior to cash deposits being involved.