RCS Debit order without my consent

In March 2019 money that I did not authorize was debited off my account by RCS. I made contact with RCS' accounts department and they told me the transaction in particular is not reflected on my statement with them. I sent them proof of debit from my bank statement to which they acknowledged that the funds were removed and following that i received no further correspondence.

I kept requesting feedback and they respond two months later in May asking me to send the same statement they had acknowledged in March. I send them the statement and I don't hear back from them again for a full month.

After I send a mail telling them that I was afraid my approved debit orders with them would disappear as well I get told my query has been escalated. Again I don't hear back from them for another month.

A month on from that after asking for feedback I get told the matter has been escalated again.

FOUR months later with no response I cancel my debit order with them. I get a call from them in January 2020 requesting payment, to which I explained my story and was then asked to send statements and email correspondence.

Another month on I still don't hear back from them. Eventually they call requesting payment and I repeat my story and send statements and correspondence. I keep calling and sending them mails for another FIVE months. I get a response from them in July asking me to send my bank statements again. I send the statements and again no response. I reported the matter as a ********** case to their ***** department and still they couldn't help me

I sent them the list of questions below and STILL no response;

1. Why was that money debited without my approval? 2. Why do they keep acknowledging the debit but have done nothing about it? 3. Why that amount does not reflect on my statement? 4. Why do they keep adding interest to my account which would have been settled had the amount been acknowledged and the matter resolved in March 2019 6. How will they resolve the issue of this account reflecting negatively on my credit score with months of non-payments reflected for money they took. 7. Is this a ********** case.