oh that sucks.
I have knowledge of the place you went to and personally wouldn't go back, had to threaten legal action before he would provide remedy. If you spent a lot of money maybe get a more professional garage to check the work for a possible money claim (if they can generate a report for the claim)...
In your photo the top of the gearbox looks very moist, maybe its a long shot but check that the bleed nipple photographed is actually closed properly. If you do find it open or loose I can highly recommend a reverse flush as per the thread below.
https://www.the75andztclub.co.uk/for...=reverse+bleed