Fujichants, creep, indeed! I'm inclined to think that the mechanics actions were more than mere social blunders. The impression that I received from your post was that you did all you could to spurn his actions yet despite that he went ahead and made inappropriate advances. I'd make a formal written complaint to the manager/owner with a detailed account of what happened. That way you can keep a copy and notify the LBS without having to speak to them in person. You should clearly spell out for them every instance where he acted despite your protests. Whether the LBS does anything or not at least you they've been made aware of the events that cost them a customer and you have a copy to file with the proper authorities if the mechanic should ever try to contact you in any way again.