Yea, so the guy never warned me but in the terms for debichecks you have the below:
"DebiCheck mandate can only be disputed if a different amount was debited against the customers’ account, or the date on which the amount was debited to the customers’ account is different to what was agreed to in the DebiCheck Mandate"
Since one has approved R20k then they can deduct that and bank will tell you to bugger off deal with the SP.
This seems very wrong to me as none of my other debicheck mandates are so grossly disproportonate, car, life insurance etc are all actual debit amount with a max of ~20% more. If the provider wants to ammend it then they can resubmit a higher debicheck amount.