The Sales people are robbing the customers!!!!

I have been battling since 4 months ago to get my query sorted out. I did an upgrade in December. When the bill came is was double the amount and when I called MTN they said that I have been charged for a devise that I never agreed to. Ever since then I been fighting with Mobilesplus to correct my package and to refund my money for the last 4 months. Everytime I call them it's just excuses excuses this 1 is waiting for that 1, what bull is this???? I am really fed up and I will now take the legal route because this is *****. I am unemployed and battle enough I dont have the time and energy to fight for my money really now.....