Mtn need to be held accountable

When I app**** for a contract, it went through Mondo mobile- because of their incompetence I have not secured the sky sim on the black Friday deal. Months later I was only able to apply again and got a sim but now I am paying more than I should have been. My agreement with the shop salesman was that roaming would be activated. When I went to Namibia, roaming was not activated. My customers were unable to contact me. Two weeks ago I was in Uganda. My roaming was activated finally. People from South Africa can call me when I am on roaming and I can call them but people in other countries cannot call me whilst I am on roaming. I also allocated only R500 to my roaming expenses. Now I get invoices for amounts which I am unable to pay. Please, this needs to be investigated and the mtn staff held liable. I have lost at least R500000 in sales per month because I was unreachable. Mtn must be held accountable for their *********** staff members who give incorrect advice.