Personally speaking, I would make the trip back and tell them to fix it right, then I would see about finding another dealer, I mean you did PAY them to service it and since they obviously didn't work on the bobbin, they did to make good on their service. Also I would talk to Bernina HeadQuarter's and complain about this dealer. You certainly pay through the nose for a Bernina, along with the fact that you have to have Bernina bobbins, Bernina feet, etc., that you also pay through the nose for.