Is Renault my only option for resetting a warning light?!?!

[Emmabunny45]

Hi all

I've got a 1.6 16V 2004 Megane that I've had since December 2006. Had no real problems with it until January, when the electric windows mysteriously opened themselves and stuck in the down position. Even out of warranty, Renault fixed it and just charged £19 apparently for the part.

Since then I've had 3 problems with the Toxic Fume filter light. The first time I had the flashing light and got the eggy smell and bad performance so immediately took it to the Renault delaer who replace an ignition coil (just the one) and presented me with a bill for £100. At the same time the car is making really bad squeeking noises all the time when driving and also when braking. Renault said they didn't know what it was but said something about the brake pads (or disks?) binding and said they could separate them for another £100 but couldn't guarantee it'd fix the REALLY LOUD squeeling.

9 weeks later the toxic fume filter light came on again, but this time without flashing and the 'SERVICE' (not spanner) light was also illuminated. The car also started stalling every time I slowed down. This time, Renault said it was a faulty camshaft sensor and charged me £200 for the repair.

2 weeks later the same lights came on again, although the car was driving well (besides the REALLY LOUD squeeling noise). Thinking it was the same fault, I took it back to the garage. This time they said it was a faulty heater thing on the downstream oxygen sensor - and wanted £200 to fix it. This included the service charge FOC! The man said it was to do with the emissions and that it just meant that the car would fail the MOT. I asked if it was safe to drive and he said it was, but that I should get the work done sooner rather than later. I took it to an independant garage (owned by a friend of a friend) who's computer diagnostic thing couldn't trace the fault. He replaced the part that Renault said needed doing but couldn't reset the warning light. He then took the car to another nearby garage with more sophisticated diagnostic equipment but their computer couldn't recognise or reset the warning light either.

Is my only option to go back to Renault? I know they'll charge me £60 to hook the computer up and I just know they'll find something else to charge me for!

Thanks very much in advance. I love my Big Bum but am near the end of my tether with it!