Have had three genuine problems with BMW kit and spares over the last four years which my local BMW dealer was a total ar*e about, refusing to rectify the problems and lying to me regarding the sales of goods act and warranties.
BMW customer services , however, dealt with all three problems very quickly and efficiently and resolved the issues without it having to go as far as the small claims court which I was more than willing to do.
Just make sure of your rights , give the dealer the chance to sort things out and have anything they say or do confirmed in writing or verbally with a witness then put he facts to BMW .
If you still get no joy on a genuine complaint take them to the small claims court and make sure the national motorcycle press get wind of it if the results are in your favour.
With all of the issues I had they were genuine well recorded faults with kit and spares that had been well recorded on this site so I quoted that to BMW .