telephonic summons for scan done in 2012!

I received an invoice on 29.01.2015 for an outstanding payment of R359.00 for a scan that was done on the 13.09.2012. I paid the amount monthly and have now been by Susan from the in housed legal dept that there is still an amount outstanding of R155.09. according o her records, no registered post was sent through with the summons, nor was there any proper investigation sent through from them for the last 2 years requesting payment! she was unprofessional and clearly didn't know what she was talking about! I will take the matter to small claims court cause I am now being harassed for petty amounts! I will also take this matter further to the media and expose Lake Smit for this *****!