Unhappy customer

I have had an account with Jet for the past 30 years but recently they service is terrible. Firstly I was not told the account is being handled by RCS and I must pay handling fee of 75 Rands and month also my account always been 6 months interest free,but now every month they will add plus minus 200 in your account. My balance is February 750 I paid 350 thinking I will settle the other half in March,but am.bavk to square one owing 611 ,agents don't have explanations . They can call you everyday for money but when you request statement you don't get and nobody want to send me the sms or email that was sent to me to say the account will be handled by rcs and I will pay for that and that 6 months account has interest......jet has just become ********** over night and they don't care about their customers they signed whatever deal with rcs for us to pay for it, they don't even deserve that 1 star.they doing ****************.