Wrongfully charged monthly

Good Day, For years I tried to get this magazine subscription cancelled without any assistance from TFG - Then on 20/05/2017 the consultant, Gary (I have his surname on email and can provide the relevant supporting documents) confirmed that it has been cancelled with reference number ***5B however I am still being billed for it and interest is changed monthly! I tried to phone multiple times but my calls are always put through to different departments. I want this cancelled and my money refunded on my account as this was wrongfully charged for years and is surely ********** as I have confirmation that it was cancelled - why did I receive a reference number if nothing was done? I am spending more and more money trying to get this sorted out with nothing happening. I have emails where consultants are saying there is nothing that they can do - so who can assist? I want this cancelled and I want the incorrect charges all reversed on my account.