On air sold me contract and I war ill informed.

I have been ill informed by on air, I have two decoders and two dishes of DSTV that I am paying in total R198. Somebody calls me at on air and tells me that on top of R198 I will only pay R40 and total of R238. I only realised when they have changed decoders that its a new contract altogether, meaning I pay R198 and R238 and have 3 dishes. And 24 months contract for that matter.