Telkom Service Sucks with their Overcharging

About 10months ago I took a telkom router contract, firstly it was meant to be 20 gigs during the day and 20 at night but to my surprise though we would be at work during the day and wife off ,it never lasted for more than 7 days.Actually it was by like it is gets to 7 days.To top it all they then decided to charge me R500 extra instead of R359 which means for the past 3 months I have been charged R1500 extra.Went to their branch in Sandton in July where they told me someone was going to call me and have this sorted out but no one called me and again this month I have been over charged a R500 and when I call asking for my money back they tell me it can not be reversed it.

I regret taking a contact with this useless service wanna be providers.