UNABLE TO CANCELLE MY SERVICES

I have been trying to cancel 2 of my contracts which have expired and to move one number to pay as you go. I have tried through the service number 084145 and each tie they transfer me to cancellations, the all is cut. I have tried the cancellation number 084143 and each time the message is that this service is not available. I have been trying for 2 months. I have had my personal number for 15 years and don't want to loose it, I just want to transfer it to a pay as you go.