2002 Starting Problem

Hi All, my wife and I have/had a 2002 Grand AM, we got it on 02 and The car has been in perfect shape ever since.. no major problems what so ever, The only things we've had done to the car are new brakes (about a year ago) and a new battery.. That being said, we recently bought a new car and we decided to give my mom the Grand AM.. She has a 95 saturn and it isn't too reliable.. Ne who My mom has only had the car for a couple of weeks and she takes care of it pretty well, she doesn't really drive fast or anything.

So my wife has a friend at work whos husband manages a garage and my mom took it to his place to get the headlights adjusted and get an oil change. So she does that and not more than 24 hours later, the car stalls and dies on her at a red green light, the car behind her almost hits her, but she got it started and was able to get to a CVS parking lot and she got a hold of us. The car doesn't want to start now, She had mentioned she just filled it up the day before, so we were thinking maybe bad gas, but she said she filled it up before the oil change.. I checked the dip stick and the oil is new and it's full, so I'm pretty sure them forgetting to put oil back in the car would be the problem.

The car doesn't want to turn over when you turn the key, the lights and everything seem to work fine as well. I know the Oil filter and what not are hard to get to on the car and a few things are needed to be removed before they can change the filter.. But we don't know anything about cars so we're not sure where to start. We called the Manager up and he said an oil change wouldn't do that (Obviously) but is there anything they could have forgotten to attach or anything like that that could cause this big of a problem?? Sorry for the long post I'd greatly appreciate any help on this.

when you tried to start the vehicle, was there any clicking noise like the vehicle was attempting to start and does the security light flash during this time?