Dont want to pay

I was reffered by my gp to lancet lab to get blood test for my son allergy, while I was by the lab I called the descovery medical health to find out if they cover on the test, I was told they cover and I could go ahead with the tests,I went ahead and done the test and Lancet sent descovery and descovery keeps rejecting the claim saying they do not cover for for the tests that were done for my son, and now the lancet is on my head calling me they want their money now I owe them R2700, I must pay them for the tests descovery keeps promising me to get feedback if they will pay buti gues they are still investigating the issue its been 3 weeks now they sent me the email to say they wont cover for the tests. I have 3 consultants who called me about same issue but nothing has been done.