Cancelation of TELKLOM LTE wireless Contract - No Service!

How long does it take to cancel a LTE broadband wireless 20GB contract that does not work?? According to TELKOM you must complete a contract cancellation form, which I did complete in January 2018 and then wait for 30 days for the cancelation to be processed. After even sending their technical team to my house to double check that I really do not have LTE signal they still do not cancel it and still the debit order goes off every month. I am still waiting! You sold me a product which does not work in my area. 5 MBPS is not LTE. My 3G is quicker and more reliable. TELKOM have done all the tests and yet you hear nothing from them with regards to my complaint and cancelation of my LTE contract. Only takes your money every month for something that does not work. I have e-mailed & phoned on various occasions since January 2018 with no luck too date. This is really ridiculous and unacceptable!