Webafrica *****ing money from my account

I have been having a huge problem with WebAfrica. After I canceled my services with them I needed to return my LTE routers so that I don't get charged for them. I did as the requested but they kept sending the courier back refusing to accept any packages, this was the week just before the national lockdown started. I understand why they did not want to accept any courier packages. But I did contact them and I asked them to then not debit my account as the fault was not on my side and wait until the receive my routers after the lockdown before taking money from my account. They said they won't, but to my surprise, they debited my account at the end of march with R5700.00 and I reversed it, I then called them again to arrange with them to wait until they received my routers before deciding to charge me and they "made a note" to ensure it won't happen again, and again at the end of April they debited my account with R5744.65. I am not able to reverse the debit order and the Webafricas billing department refuses to answer their phones. So they are actually *****ing from me and this is not acceptable especially with everything that is going on at the moment. There is no response from their side.