Incorrect data package

Firstly thank you very much to Sibongeleni for her great service and professionalism. I am grateful to have gotten through to her , she was very helpful.

I am however terribly unhappy with Mondo, I was offered a 10Mbs package with Router for R199. Last week I received an invoice from MTN stating I am to pay R880 for the line. When I phoned to investigate I was advised that I have been put on a R499 a month package without my knowledge. Mondo has went back to the recordings and found that their agent did indeed sell me on the R199 package not R499. however Mondo now wants me to either pay a fee for the downgrade or pay the premiums for 3 months at R499 if they are to cover costs for the downgrade. Now personally I am against this resolution and feel it is terribly unfair to myself as a customer ,I cannot be liable to pay for a service I did not want and most definitely not willing to pay Mondo to rectify their own mistake. I am unhappy with the service and I feel de*****ed because where does Mondo get the right to make financial decisions for me. My assessment is Mondo should put me on the correct "Unlimited package" at the agreed upon price, settle the R880 owed to MTN and reprimand their agent for lying not ask me to meet them half way.