Taking a clients money and not sending invoices to medical insurance!

I received an account from Medicross this month for doctors visits (dating back to October 2017!). The account was never submitted to my medical insurance and they also do not indicate the payments in the amount of R 50 that was made with every doctors visit. I stopped going to them after being advised early in March 2018 that they are no longer contracted with Essential Med (my medical insurance). The practice was recently taken over by Medicross. I do not understand how they can send statements with the wrong information to clients. This is the second time that I experienced this with that practice. I would suggest that Medicross firstly ensure that they have the correct information at hand before sending statements to clients. I will never make use of Medicross doctors and hospitals after having this experience.