SAFETY!!FAULTY AIRBAGS

We all seen the news of the safety issues with airbags of some of the models.so we took our car in coz for a longtime the airbags light came on.well Rola vw Vredenburg worked on it and the light was off,we thought okay all good,just the next day it came on again,now they are telling us we should pay coz there are bigger problems if the light when on again.How do we know that there are bigger problems? How do we know they did a good job with airbags?These people will rather let you pay for there mistakes