Unprofessional Service

I asked J Donaldson to repair my dishwasher, electric oven and microwave in March 2015. The microwave and oven were repaired and returned within 2 weeks but up until now (11 July 2015) they have not returned my dishwasher. After repeated phone calls and promises that Whirlpool were not sending them the correct parts for replacement, now we were told that they cannot repair the dishwasher. They have also promised repeatedly to return the dishwasher but have failed to do so. I am now extremely frustrated and have lost all trust in their business ethic.