Immobiliser Warning Light

Car cut out yesterday,no power other than radio & clock.Immobiliser light flashing,thought my key was kaput,called RAC , while waiting I tried ignition,couple of times all seemed normal ,no immobiliser light, starter motor turning engine not firing,then immobiliser light on again. RAC man came and said it was the key and advised getting local key-man out,he did not use his code reader. The key-man came later and said RAC had called him to brief him,he told RAC he did not think it was the key but would come and check,did test,said car computer was not talking to his computer but it was not a key fault,RAC came again,different man and towed me to a garage in my home village,pm,spoke to garage owner at home who said he was off on holiday this morning for two weeks. Anyone out there

know what I can do to fix it,bit !Removed! off that neither RAC man got out the code reader and tried to diagnose.