bad administration nightmare

I took my family to Mkem on 9 May 2015 for travel injection and flu vaccinations. I paid the full bill with my credit card before we left. Eversince I keep on receiving outstanding letters in the post, first for my daughter D Bosch for the amount of R59 not paid.. I emailed the proof of payment to Mkem on 10 June 2015 and requested a confirmation that all was in order. No reply received and guess what I found in my post this week. An outstanding account for D Bosch and now also for my son X Bosch also for R59. Now they threaten me with legal action if I dont settle immediatley. What a joke. Waist your money on sending bills and legal action. Rather spent the money on getting your admin sorted. You may be open 24/7 but your admin is not operational at all. I will not be using your service again!!!