Billed unfairly

I cancelled my contracts by paying in full. Have the quotes as proof. Their negligence in detecting this and then not deducting my fibre led to a double deduction with an added tarrif on my bill. I do not recommend this service anymore. The view bill option on the app does not even work. I'm being billed for things I was not in control of. I asked to be called back and they have not done so.