Not inspired

I ordered blankets and was told that I will pay R127pm for 12 months, and R228 for 6 months , I decided to take the six months payment. I get an sms my balance is R1700 and monthly payment of R195 for 12 months. I called and no one could explain to me what was going on, keep being told they will call me back and no one does so. How can 127 for 12 months jump to R195 for 12 months. I'm never buying here again and this was my first time buying from you. Pls fix this immediately