Exorbitant Bill & Silence when probed

I took out the deal for R699 200GB Anytime/Day & 200GB Night and and additional R99 for the Router. I called Cell C to ensure that the bill does not go over, that for all the lines I have, the usage is only limited to what the plans come with.

Now I am getting a bill of +R1200. WHY? I sent two emails and did not get a response, instead I got a link asking me to rate the service I never got.

How pathetic is that. Please explain and refund me back. Ensure that my bill for next month is what I signed up and agreed to, please.