Incorrect billing

I app**** for a cell phone contract and during the application that was conducted telephonically was offered a router for R120 not more that that only to find that the router is R3hundred and something a month and my application was for cell not a router, router was delivered however the cell never delivered to this day and the application was done march 2020.. number 2 i upgraded my cell phone contract March and then cell was R299 a month but now i am paying R359 a month how is that possible.