FNB NOT ASSISTING WITH DISPUTE OF DEBIT ORDER

In Feb I ordered a sim card from Telkom @ R99 per month - all was done online as I do not have transport to go to a telkom shop. I asked them to port my number. After the sim was delivered I waited 24 hours and still the sim was not working. I phoned them and they said the sim was not setup and I had to go into a branch to port my number to Telkom. I then told them to come and collect the sim - as this is not what I ordered. never heard from them again until lockdown they started deducting R514 from my account. I disputed the debit order and they kept on deducting this obsurd amount which does not even make sense. Now in July they actually deducted the R514 again along with an additonal R110 for fun! When you call FNB they simply cant reverse the debit order - they cant help you in the branch and refer you from chat to phone and vice versa. How can FNB just allow telkom to deduct fees from your account?