Submitted a claim to medical aid with incorrect details

I was admitted to hospital on the 12th of March 2018 and the doctor ordered some blood tests, instead of claiming for in hospital they put it through as a normal claim which my medical aid did not pay (ALL other claims for the duration of my hospital stay was paid by my medical aid because it was submitted as in hospital) now they expect me to pay the outstanding amount which would have been paid if they had submitted their claim correctly. Rather than trying to get the money from me perhaps just re-submit your claim with the correct details. I will not pay for a mistake made on your side.