Mercedes Benz C Class Gearbox Problems

Hope somebody can resolve this for me. I have a constant clicking noise inside the car that sounds like a bearing spinning around. It gets more noticeable after driving longer distances but when I go round a left hand bend the noise disappe...

The automatic gearbox on this car when coming to a halt appears to be undecided as to which gear to be in. i.e: first or second gear and appears to shudder slightly. Can you help??

I have checked the gearbox oil level that is ok ,was told by garage who run diagnostics that the air flow sensor was faulty so have changed that but the problem is still , will it make a difference if I disconnect the battery for a while?

Third gear can't change and sometimes raises before changing