FNB Merchant services

Hi all, in 2020 during lockdown I cancelled some our merchant machines by FNB. I have the proof of emails sent. They collected the machines but since then I have been charged for one terminal plus a fee for not using it every month. I do not get invoiced for this deduction. I do get invoiced for the other terminals. Is this legal? Then in 2021 they swapped some of my other terminals but are now charging me double once for the terminals they exchanged and once for the old ones. The monies being deducted are now in the tens of thousands and I keep getting excuse after excuse and then silence. Then auto replies. So 2 questions that I need help with please. 1. Is it legal to deduct monies from my account without being invoiced 2. Is there anyone that I can contact that does not work at the call centre and will be able to actually help me.