Telkom *****ing customers

I am tired of telkom I think I'm being punished for choosing them as my network provider. 2 months back I was charged more than what I've signed for I didn't noticed until the following month they charged me double I phoned them and notify them they apologized and told me they will refund my money which they never did and even promised that this month they will charge exactly what I've signed for to my surprise when the statement comes I still owe more. Even though I canceled everything with them and never received my refund. Telkom is *****ing us I'm really tired because even if you phone their consultants they're not helping. I regret choosing telkom from day 1