The person who took care of my instrument didn’t seem very experienced, but still in the shop there were more professionals and none of them was interested so much about my problem. After a few minutes of explanation and more than half hour of trial, they placed the sound post at the wrong angle that made it necessary to remake a new one some weeks after. They made some little adjustments(glued the fingerboard corner leaving traces of glue on the lid), but the main problem(lack of resonance, depth) remained. That was unprofessional and I got the impression that they didn’t bother to investigate a little more. My instrument is a very easy one to diagnose, and there I was said that it was hard to find the solution, perhaps assuming that it couldn’t sound better. Very frustrating, but fortunately after replacing both sound post and bridge, now it’s working again. It wasn’t as complicated as they told me.