HUGE Let down with service

Worst service I have ever received I logged a call to relocate my fibre line after a struggle they told me that the line can't be relocated because there is not fibre in the area but it does show live on their web site, after a long struggle I have agreed that they can cancel my contract I have signed and send in the documents to them twice and I have asked them for the banking details to make the payment for the remainder of the contract I was told that they can't give me banking details it will be a debit order after a while again I followed up to ask when will the debit order be taken with no response from them this was around March 2020 up until June 2020 and in the time I have forgotten about this, I have not in this time at all received a invoice or statement from them, they did not call one time or even send an SMS now in November I get a call that my account has been handed over to their legal team for collections. How do you hand over an account without an invoice or statement or a phone call, How was I suppose to know what to pay end where to make the payment to. This is really the worst service I have received.