I want my money back

I called in July to change my package as I was paying for high-speed but highest speed I would get 10. I was called and promised a technician would come and nothing v happened come August I called to cancel my subscription and I was thn sent an email that my cancelation request was received ref number *** the I received another email on the 16 August after speaking to agent that my cancelation has been scheduled. The end of August I made a payment. To my surprise end of September rain debits my account and on Facebook I am being told that I cancelled in September how... When I. September I did not even use your device. I have been calling, sending complaints on Facebook I am not getting help.. I want my money back plz.