Misleading into a contract

Mobile talk called me and sold me a Wi-Fi router and I told the person that where I live there is no talk on coverage but she insisted it would work...

I called telkom for clarity and they said it can only be checked when the product is active, once it went active, the product was roaming and it used up my allowance which I was not informed of, now instate of my monthly +- R300 debit, they deducted R1600 and they still not resolving the issue and I cancelled my contract, they haven't sent a courier to pick up the device...

It affected my budget and my living condition dismally...

I'm very unhappy about this...