RCS keeps adding funds even after it has been paid in full!!!!

last year in october my debt review company finished paying my acc in full with RCS CORICRAFT. i phoned rcs and requested a paid up letter-nothing happened, for months. my debt review company has also requested paid up letters from rcs and they also received NOTHING. now 6 months later i get a court summons for an outstanding amount of over R500. what i dont understand is how rcs can add over R500 in funds if the account was paid up in october...i have all my statements proving that my rcs acc was paid. they dont help and they dont sort their **** out, they just want more money. this is the 2nd time this is happening that it has been paid up yet they dont close the account or give me letters that its paid up. more funds get added every damn time...