WORST EXPERIENCE!!!!

I took up MTN Shesha which was advertised as 600GB but it's not. At first the consultant **** and said my first installment will be in July but it was actually in June after I paid a prorata of R700 and something, I asked for a black router he agreed instead of telling me it's not possible I got a white one. Now I am trying to upgrade because they said we can do that and they are saying no I have to cancel this one I'm on go to an MTN store and return the route then sign up for the new one. This is the worst customer service. Dishonesty at it's best. You should be making the customer's life easier and stop over promising and under delivering. I need this issue resolved. I need to upgrade and I don't have time to go to an MTN shop. Why can't the ones that deliver the new router take the old one? Most companies do this once you get the sale you no longer care about the after sale process.