Intec refuses to help

I registered in September 2020. I submitted multiple assignments. I asked repetitively for feedback and marks. They ignored me and did not mark my assignments. In June 2021 I requested a cancellation. Again, numerous requests for feedback and assignments still not marked. They removed their debit order when I put in the cancellation. In August I recieved a letter stating that they would cancel the account if I paid them a rather large sum of money. According to them they had fullflled their legal obligations. I called and asked if marking assignments was a legal obligation according to their contract, they confirmed it was. I argued the cancellation decision, insisting on a refund for the money I paid as they wasted my time and my money and did not provide the service I had paid for. More requests for feedback followed. 01/10/2021 I recieved a call from lawyers stating that INtec had handed over my account for non payment. They had not contacted me in all this time to say anyhting about payment. I called the call centre, they left me on hold for 10min. I called twice more, trying to speak to their cancellations department. I was told by the extremely rude representative to wait on the line. I tried to speak to their collections department and was told that they could not help me. They are ruining my credit rating and that of my husband and they keep extending the estemated time for an answer on the matter. They refuse to assist with anything and just keep telling me to call the next week. I have all the emails and also a detailed list of the dates of all correspondence.