Fortunately I've got no problems with either of the chaps who instruct me. However I'm at a satalite operation so the chances of me ever seeing the CFI are ZERO.
However I'm big enough to talk things out if they arn't going well (currently cr*p at landing but with only 7 hours what can you exepct). If I'm not happy I'll vote with my feet and wallet - they know this todays market is pretty competative.
NOT that I'm likley to of course.