This shop could teach a class on how to shoot oneself in the foot. How much can a 105 triple front cage cost, relative to a double? How much good will and future business, by comparison, is this costing them? How much is it costing them to send someone down to the courthouse every time they get spanked trying to be Scrooge?

Compared to the potential loss of business and community good will, the cost simply to give you the right derailleur is couch change.