I BROUGHT MY CAR IN TWICE TO HAVE A OIL LEAK FIXED AND THEY STILL HAVENT FIXED IT. HELP!!?

I HAVE A 94 TOYOTA CAMRY. IT WAS HAVING A PROBLEM WITH LEAKING OIL AND SMOKING FROM UNDER ENGINE. I TOOK IT TO THE MECHANIC AND THEY SAID IT NEEDED TO HAVE THE VALVE COVER GASKET REPLACED.I TOLD THEM TO GO AHEAD AND FIX IT. THE DAY I BROUGHT IT HOME,IT WAS STILL SMOKING AND HAD A SLIGHT OIL LEAK. I BROUGHT IT BACK AGAIN AND THEY SAID IT WAS THE CAM SHAFT SEAL THAT WAS LEAKING AND NEEDED TO HAVE IT REPAIRED. THEY FIXED IT,I THOUGHT THAT WAS THE END OF THE PROBLEM. A FEW DAYS LATER I NOTICED OIL SPOTS ON MY DRIVEWAY.A FEW DAYS AFTER THAT THE CAR STARTED SMOKING AGAIN. THE MECHANIC IS STILL TRYING TO CHARGE ME FOR THE CAM SHAFT SEAL THAT WAS REPAIRED ($120) AND IS THAT I WOULD HAVE TO PAY FOR FURTHER REPAIRS TO THE CAR TO GET THE OIL TO STOP. MY QUESTION IS-WHAT ARE MY RIGHTS IN THIS SITUATION.I DONT KNOW ANYTHING ABOUT CARS AND REPAIRING THEM AND AM AT THE MERCY OF MECHANICS. I BROUGHT MY CAR IN TO HAVE A OIL LEAK REPAIRED AND THEY JUST CANT SEEM TO FIX THE PROBLEM CORRECTLY. AM I LIABLE FOR FURTHER CHARGES TO REPAIR THE CAR BY THIS MECHANIC? IT IS NOT MY FAULT THEY COULDNT FIND THE SPOT OF THE LEAK IN THE FIRST PLACE AND DONT THINK I SHOULD BE CHARGED FOR THE 2 REPAIR JOBS AFTER THE FIRST ONE BECAUSE THEY DIDNT DIAGNOSE IT CORRECTLY. HELP,NOT SURE HOW TO HANDLE THIS SITUATION. IVE NEVER DEALT WITH SUCH INEPT MECHANICS. ANY FEEDBACK WOULD GREATLY BE APPRECIATED. THANK YOU!I BROUGHT MY CAR IN TWICE TO HAVE A OIL LEAK FIXED AND THEY STILL HAVENT FIXED IT. HELP!!?
welllllllllllllllllllllllllllll now you gotta do what you shoulda done//go to dealer and get diagnosis and estimate//your paying now not to fix it