False marketing and hopeless service

An RCS promoter cornered me in a Pick n Pay store some weeks ago, and invited me to apply for a store account - 55 days interest-free, R200 off your first purchase of R500 or more. I was approved for an account and was sent a screed of information about it, from which I gleaned that there is a R10/month account fee (not mentioned by the promoter). I sent an email query about this but received no response - instead, a second screed of information arrived with no explanation of whether this replaced the first lot of documents. With some misgivings, I made a purchase on account for the first time on Sunday 29 October, totaling about R1,917. When I asked about the R200 credit the cashier had no idea what I was talking about, and the customer service desk told me I must phone the next day to request this as the store account people do not work on weekends. My intention was to activate the credit and then pay off the balance in full within a day or two. However, I've now been given a run-around all week, both by Pick n Pay and by RCS. The promised R200 credit will apparently only be app**** at the end of November and in the meantime (regardless of the advertised 55 days interest free) interest is already accruing to the account and a R10 account management fee has been levied. I spoke to team leader Dylan van Wyk at RCS today and he advised that their system automatically applies interest from the date of purchase and then reverses it if the customer pays within 55 days. Given how many financially unsophisticated people we have in South Africa, I believe that this is inappropriate and confusing. I will pay the value of my purchase less the advertised R200, and (under objection) the R10 account fee. I will then close my Pick n Pay store account because I don't trust RCS to treat customers fairly.