Abuse I receiving daily Mr Price money

The bad treatment, mental anguish put me through receiving calls non stop inspite of making monthly payment arrangements. My account was handed over to ACS of which agreed will pay monthly installments till finish paying. My crime was to ask statement since I started paying felt the monthly interest rate is high after that all hell brake loose being called more than 5 times mind you they told each time they calling, sms, email being charged. It unfair to charged for while made arrangements to pay and have not defaulted paying since. I paid on 27th October and the following day sending massage to pay full amount or taking legal action already added 70rand interest day after I have paid monthly installment. This is so wrong just want to finish paying I will never ever again do any business with Mr Price.