fan blower is getting very noisy
 

i bought a mazda cx9 for 6 months now...it did not come with the Nav..so i decided to get an after market one for it later. shockingly it brought me a lot of nightmares after i got the unit installed in...firstly i got the AC did not blow out the cold air, i then took it to the dealer and got advised that i have to resume the car back to the factory setting condition that means i must put the original audio unit back in order to get the AC working back normal. I brought the advice back to the audio guy who installed the Nav in ( Blaupunk). Surprisingly he told me to let him fix up the AC. He ended up sorting out the Ac working perfectly. Yet, soon after i took the car back from him i found out the font fans got automatically turned on constantly ( non stop) when i turned on the AC and they are off when the Ac got turned off. I brought it back to audio guy and told him the whole story about the fans, left it with him for a day. Again he fixed up the fans perfectly. however there is an issue still exists now is the fan ( one fan) getting very noisy when it is on and again non stop like before. That i still remember from my best memory that both the engine and the fans were quite quiet when they are on once i bought it ( brand new )

I got stressfully stuck on it and don't know what to do now with the car as i cant bring it back to the dealer due to not following his instruction at the first stage. With the audio guy i don't even want him to touch in any part of it.

Anyone can give me a tip on what to do now !!