Leaving and no contact

I have made various phone calls and completed a number of online chats to try and obtain confirmation that my contract will end on the agreed date ( no way was I prepared to accept the renewal jump from £69 to £215 per month) and each time I speak with someone, I receive a different response. 

Is this common practice? How long should it take to receive confrontation? 

I have saved the chat transcripts to confirm what was agreed in relation to the cancellation, but still not received anything in the form of email or changed to the account - when logged in, the account suggests my next bill will be £200+

The hours wasted trying to resolve this is pretty ridiculous and is really frustrating. 

TIA