Volvo S40 1.8 Petrol 57 Plate - Immobiliser - davidhay

I have recently just my vehicle serviced and the day after, I have attempted to start the vehicle and it refuses to start. The error message has come onto the dashboard "immobiliser, see manual". I have checked the manual and I am unable to locate any information in relation to this. I have looked onto the internet and the advice has been to open and unlock the car five times. This has not worked. Can anybody please advise.Thank you Dave