Not willing to cancel

We have tried for 6 month to cancel a contract, we are promised that they will send us a copy of the contract that we originally signed and we have spoken to their call centre who told us they are unable to find the contract yet they still refuse to cancel the contract. We get no help from the call centre no one senior is willing too take your calls. We have tried everything yet no one is willing to assist at all. The call centre is so bad they will say they are transferring you and either end the call or start singing on the other end. This is an utter joke.