******* offers made phone. No wonder DSTV is in trouble.?

We were offered - by phone - a revised contract for a further 2 years at a reduced rate per month. The next day we get another call offering us a a second decoder at no extra cost. We reconfirmed this a few times by the caller. The new decoder was installed. A few days later we received a call saying that the DSTV agent that called us about then reduced offer with the 2nd decoder, had made a mistake, and now our premium would be raised substantially. We told them to remove the decoder and reduce our premium to the initial agreed lower premium. I find this completely unprofessional and smacking on being ******ionate.