Great service very poor after service

Good Day I just want to write a review on langamed ambulance services, in 2019 they had to come and pick up my 2 little boys at home and take them to the emergency room at the hospital, for that service i will say great they responded very fast and swiftly. Now since then i received a account from them that had to go through to the medical aide for my eldest son. they said that my son is not on the medical aide so i have to pay the account out of my pocket so my argument is as follow. why would my youngest son be on my medical aide and my eldest son not. Now i am being harassed by their lawyers Nicol & Davison to pay the account. I have told them numerous times that i will not pay a account out of my pocket because of a mistake that was either made by Medscheme or Langa Med ambulance Services. currently i have nothing good to say about either companies. i just want to get this out to the public so that every one can chose their operator wisely.