Misleading contract

Telkom is one of the cheapest networks in South Africa, however their contract charges are ridiculously expensive. I took a Telkom contract via Mondo, and no one explained to me how their charges are made.

I called them and spoke to one of their consultants to let them know that I was canceling my contract due to unemployment, to my surprise I was charged R350 more than my original amount of R200 and I was told it's interest to this point I'm owing to them R1900 which I do not understand. So be very careful with these contractors you might end up paying an arm and a leg.