Mtn overcharging

Upgraded cell phone and internet. Cell phone contract price R299-00 per month I am been billed R349-00. Internet contract price R259-00 been charged R549-00. This is the first time I have renewed in nearly 20 yrs that the contract is nearly double to what I chose.Have hit a brick wall with Mtn call centre and the greenstone branch. I live on a very strict budget and changed to a contract that includes talktime and data bundles. My previous billed accounts used to be over R1000-00 so these two contracts where a saving to me of over R400-00, but its costing me R950-00 per month WHATS UP are we paying for the retrenchment packages