how can i stop the air bag warning light flashing on my nissan micra 2005 m?

nissan micra s 05 plate passenger side air bag warning light flashes. Serviced by my local non specialist garage who reset it and told me it had an open circuit the reset lasted 2 days.I used the net to reset it myself but each time it only lasted 2 days.went back to my local garage who rfered me to go to a nissan garage.I know if i do it will be an expensive job. is there any one in the Torbay area who does this sort of repair at reasonable cost ?.