Terrible service MTN

So on the 9th of September i app**** for a data contract with MTN ,which included the sim card and the mobi router, days later someone calls me and we complete the application over the phone and I'm approved. So im told to await delivery in 3-7 days, which didnt happend. After having to DM them on twitter i get my delivery after 3 weeks and guess what no mobi router just the sim card. When i do enquiry on via DM's again im told that their system only shows the application is for the Data sim card. I had to send a screenshot of my application only for them to say to me they will see what they can do. its been 4 days and there has not been any communication from them but come month end ill be billed for something i never used. What do i do? Cancel this contract?