My 80 y.o. mum had a procedure carried out in hospital last Jan. She received a letter from the hospital recently informing her that her claim was rejected by the insurance co., and she was subsequently billed for 1,500 euros! She contacted her insurer and they told her that the consultant in the hospital could not be contacted, or else refused to respond to the insurer with regard to her claim, so her claim could not be processed. She pays heavily out of her pension for her health insurance. This has never happened to her before. Why would a consultant refuse to speak to a patient's insurer? And how should she proceed? Thanks.