paid up account handed over

hi i went to the cellc branch in kolonade a year ago to pay up my accounts and close it. so the girl working there gave me print outs of what i need to pay to close the account including the last payment at the end of that month. i went to the money market at checkers hyper in kollonade and pay all three accounts. went back to cell c and they send it trough to the accounts department. now a year later they handed my account over to mmm capital for collection. is this the service we can expect from a service provider? or is it case that people aren't doing their work. im really disapointed in this kind of service. i stil have one open contract at cell c which is paid every month, but will definitely look for a other service provider when this contract expire. never had this hassle before.