Airbag light and locks

My 2001 Hyundai accent developed a problem a month back: when I turn the car on, the airbag light stays on, and the locks don’t work. When the car is off, the car locks and the security system arms just fine. I brought it to the dealer. They kept it for 5 days, and finally replaced the battery and a fuse (and my belts which they said were in bad shape). It worked fine until last weekend, when the airbag light came on, and, sure enough, it won’t lock. It’s due to be returned to the dealship, but I’d like any preliminary opinions. Thanks!

The fuse blew the first time for a reason, and whatever that reason is, it has likely blown the fuse again. This time they need to find and correct the fault, not just the symptom.