Cancellation impossible

I have been trying to cancel my account with them for the last month now and they are making it impossible! I have sent in my notice on the 1st of the month thinking that it will be smooth sailing only to find out 2 weeks later that they haven’t “received” my cancellation which means I am going to have to pay for another month. So I sent in another cancellation and still no one has gotten back to me and everytime I call them no one can help me , the fibre still isn’t working at this point though and I have been invoiced for the last month and still no one is getting back to me.

Supersonic Fibre