Charging DOUBLE for my monthly bill!

Good day, Telkom will not respond to my query relating to me being charged double for the past 3 months!!! My initial contract states that my payment is R500, plus an additional R150 for insurance. For the past 3 months I have been sent a statement for R1,700 (double the amount of what I was initially quoted). I cannot believe they would try and ***** me over like this!

I would like someone to call me back asap - this contract is now null and void.

I await your call.