Bad service/ account handling

Now that Cell C is in finacial difficulty they tend to ***** from their clients to make up some money, the reason I say this is because of the following: My old contract expired 08/07/2020 but had already done upgrade in March 2020 so the new one took into effect 09/07/2020 paying the pro-rata for July is not the problem, the problem is paying the full month of July for the old contact and still paying for the new meaning paying for two contracts this is cost is in the region of R 1000.00 but sending mail to customer care did not help they just referred me back to the branch that did the upgrade and untill todate have had no response from the branch. I have no problem paying pro-rata on the old contact untill 08/07/2020 which to me is the correct way, not to pay old contact and new contract in the same month.