BMW Bad after sale support

Im very dissapointed in BMW as it seems that its after sale service went down the drain why is it they want to sell u cars but not help to maintain it Its so bad that some does not even have the correct tools to fix your car Others put to much oil in or update the software and blow up the engine But that is not my problem I bought a second hand x5m ne and fix it at an approved dealer Did everything i can but it gives me a engine warning when i increase the boost sometimes bit go away Now i wanted to book a diagnostic with bmw to see if its a sensor or what U know what they say Its an ols car 2009 and we scared to blow up your car Experts is scared Why They are the ones that created the software and stuff but now they scared Where is the old diagnostic machines then No man No wonder BMW is sales is going down the drain in sa Your mechanics is the doctors of BMW and then u to scares to operate Then u call yourself Specialists U can call me *** Come on tell me im wrong