Contract Cancellation within 10days at No Charge

A Telly Sales Agent contacted me & arranged a data router package for me. I was told the router was portable & if it turns out I was not satisfied l could cancel the contract at No Cancellation Fee as long as it was within in 10 days. Upon receiving the package l discovered it was not a portable router, & since l am a blind person l can not use the data during the night l need a portable router to move around. I contacted the customer care centre & was informed that l could return the package at the nearest MTN Branch. After 3 days l took the package to MTN Tygervalley Branch where l was assured that l would receive notification of cancellation shortly & to my shock instead of a note of cancellation l received an invoice where l was billed 1&half months subscription of the data package. I have tried calling the call centre & sending emails numerous times seeking to have the charge reversed to no avail & l have had my service suspended & had to pay R650 to have my service reconnected & escalated the emails trying to get the payment credited back to my account. Instead of getting the payment credited, l was further invoiced for the cancellation fees bringing the bill to R3132. Inspite of regular email to them, all l get are threats to suspend my services if l don’t pay the amount. I now l have escalated the emails l send to them to 3 times per week just to have the issue resolved. & the response is always the same an agent will contact me within the next 24hours. What a lie. What do l need to do to get MTN to do the right thing??