Consumer Protection Act undermined

My husband and I opened a new account last week and collected our card at a TFG store in Pretoria. Upon wanting to make a purchase, it was stated the 15% of the total purchase price had to be given in cash and the balance will be put on the account. This will continue for the first 3 months with every single purchase. The purchase we made was not a small amount at all, so it was a substantial amount to give as cash upfront. My problem is the fact that this was never stated or brought to the attention of the consumer during the process of opening an account. Not via email, phone call or SMS. Only when we actually physically made the purchase. The store assistant also handed us the 'terms and conditions' relating to the store account. Nowhere on this piece of paper did it state anything about the 15% cash upfront. When questioning the assistant about this, he stated 'not all of the terms and conditions are written down on the piece of paper'. What is the use then of handing this to the consumer, if the info is not accurate? TFG, what you are doing is against the National Consumer Protection Act and you are not above the law. Such information needs to be brought to the attention of the consumer BEFORE having opened an account, otherwise the contract is invalid, as there was no agreement between TFG and the consumer. How are you guys getting away with this?