MTN SA

I have a wifi contract with MTN. When I app**** for the contract they told me to pay R282.20 and I paid, I asked them how much I will have to pay on my next billing date and onwards from there and the amount I was told I had to pay was R249. I now receive a statement that states I have to pay R440.70 on 15-08-23. I was never told I had to pay R195 extra for the month of August.