failing to pay repairer policy number AIG 15405/ 1

on 14 April 2015 I was involved in an accident and I contacted my insurance company AIG for a claim .I made a choice of choosing my own repairer.It was authorized that the EMI Plastic Repairer and panel beaters can go ahead with the work.After the job done they invoiced AIG .After about 90 days I was contacted by the repairer that they were not paid even after they contacted AIG. Now after more than 120 days they complained to me that they have not yet been paid so they will be forced to recover the money from me.I dont know what is the delay is all about even after I personal contacted them.