unfair treatment

I took out a standard rcp last year and was unable to pay it for 3 months in november i called in to enquire how much i had to pay and was told i owe 3 months now to my knowledge my instalment was 1000(putting into consideration that it was above my actual repayment amount) i made an arrangement to pay everything including tht months instalment which the guy spoken to confirmed that R4000 was the amount payable that same month on my pay day an additional R1500 went off when it came to my attention i called in and they confirmed it cant be reversed i also enquired why my instalment was now R1500 and i was told it was changed i left it like that thinking my rcp will be paid up quiker a few weeks ago i went into a branch and to my surprise my account has a legal block to it when i called in i was told it was with standard bank attorneys i wonder how that is possible because i paid what was asked of me and also paying an additional 700 on my account please advise of how this work because clearly something is not adding up on my account and i need to know what it is