Poor service at Mtn

I'm Cordelia Majadibodu my no is ***,I am very furious about Mtn Lephalale,I have 2 contracts with them,I have app**** for an upgrade for my no that is new instead they upgraded the ongoing contract that is due next year,I tried to show them they mistake they said I hv signed for the wrong no,I have send them the contract to show it's the 1 I app**** for,I tried to call their HO to fix the matter they say the store must fix the matter n when I go to the store they say its HO who should fix the matter,I'm really crossed about their service its costing me.