2002 Hyundai Santa Fe Starting after fueling

History-July 02,2010 I had a trans axle baring repaired and something else I can't remember, I'm not near the paper work at this time, but anyway paid about $2,000 OK fine. I needed It fix because I was going on a road trip to Naperville IL from Milwaukee WI. Drove all the way down there on the Holiday weekend once I parked I tried to restart the car 15 minutes later it would not go forwards or backwards. I started fine.
I had my son chek the oil and there was not a drop in the car. The dealership did not replace the oil because it was not listed on the bill of repairs. I got it towed back to the dealership they fixed it and never told me what was wrong. All they said was when they fixed the leak on the tran pan may they may have dropped a screw in there, but they fixed it. OK October 23,2010 I got a tune up with new spark spugs because they said I still had the originals on there, go an oil change etc. Now everytime I filled it with gas and it won't start, it takes at lease 4 or 5 trys. I just paid 500 + dollars to get this car tuned up I do my regular maintenance and oil changes the car has never done me wrong. So whats wrong now, Can you help me?