Poor service, no resolution from call center staff, Giant company with no interest in keeping customers

*********** call center staff ( nothing new here ) on the 5th of November i did a premature upgrade , the sales consultant advised me i will continue with my current installment until December, in January the installment will change to the new tariff, i asked him repeatedly to make sure and he advised its correct, now the debit order amount changed in December resulting in it returning unpaid, the call center staff insulted me and treated me like a dumb child who made a mistake, the teamleader was also no help and they said nothing could be done.

i am not at fault here as i did my due diligence, the consultant who handled the upgrade works for vodacom and he was at fault for giving incorrect information as such vodacom is at fault and i cannot be penalized with fees and a debit order reversal flag on ITC , i am unable to understand why no one is willing to understand this and assist me, yes they explained how it should have worked but why only now after i got done in ? who will investigate this resolve this and satisfy their client ? or should i bend over get the Vaseline and take it like a prisoner ?

i have paid i have no problem with it but who will make sure my ITC stays clean and unaffected by vodacoms mistake ?