Inability to cancel TV license

I bought a TV licence with the intention of purchasing a TV in 2009. I subsequently did not buy the TV as my money was not enough and opted to abort the purchase fully. About two months later I sent an email to the email address then advertised on the TV license documents and there was no reply and I tried calling them without any answer. I forgot that I had a TV licence for a while until the bill came to me and I would try to get in touch with the department but would fail. This year I have been handed over to debt collector which called me and still are calling me, and one of the consultants said I should make an avidavit and contact the post office for the TV licences contact details, I then did that and contacted the department which then said I should send my avidavit to [Email Removed] att: cancellation department and they would come back to me in 48hours, I called 3 days later and was told they did not receive my avidavit and should resend to the same email but att customer services and they will reply in 48hours. it's been about a week and I don't know now