Mechanic refuses to refund my money

Got my gearbox fixed last year for 3.5k from a garage in Dublin. They gave me a 2 year warranty on it. After that the gearbox kept failing multiple times, more that six times, and every time it was with him for more than 2 months so had to pay an exorbitant amount on rentals as my wife has a broken ankle she is recovering from.

Last time the car broke down in ten days after returning it and he said he will give me my money back. Has been more than two weeks since then and he keeps blocking my number. I told him I need my money back before I can fix my car. He told me he would provide refund last week. Went to talk to him and now refuses to give me my money back until he gets his gearbox which he can’t arrange for pickup.

Already talked to my lawyer and will initiate a case against him to recoup all losses pertaining to rental, car value as well as any other losses. But what more can I do?