Debiting over 1700 that is not owed .Shocking

After 4 months of fighting with them to come to a resolution for a Unlimited package I could not use where I lived because of there poor coverage, or the fact they had no coverage I had use 1 bar of roaming on edge for over 7 months , when I had a s6 galaxy. it took over 4 months countless hours on the phone and over email before they offered to cancel the contract. they installed boosters that make absolutely no difference . after I handed the phones back getting a tmo number and letter stating they received the phone they still decided to debit me this is the second month they have debited me for R1700 , for contracts and phones I have not had, the same devices I handed to cellc and got a note for well over a month ago. and now are making it my problem to go through to the branch and resolve the issue. they are putting me on hold for well over 10 minutes a time bearing in mind I am working in a job I cannot afford to take this time away from work. I am tired of the terrible service or lack of service especially seeing as it is my funds they are playing with let alone the fact I was paying for a service I did not get full use of for many months