Mostert & Bosman overcharging /*****ing my fully paid account

My account was handed over to these attorneys by Propel every month they were charging me irrediculous legal fees ,I decided to settle the account to avoid this as my account was going nowhere ,they sent me the settlement letter I paid the account fully there and then ,to ,my surprise this month they bill me interest and legal fees whereas my account is on credit R980 ,this is a **************** ,when I consulted Propel they realized the error and promised to rectify it ,when I call Nadene Erasmus by the attorneys she claim it is legal fees for Apr-18 whereas they charged me R2800 included on the settlement letter as legal fees for Apr-18 whereas other months they have been charging R1700-R1800

This is disgusting and this Nadene 's attitude sucks ,