IFB Industries — Cant resolve error

Address:

mumbai

Since 3 months my dishwasher is showing f5 error…. the technician visited twice asking to replace parts for 8500rs…without guaranteeing if the F5 error would be resolved…. the technician himself doesnt know what the actual issue is… sometimes he says the drain is blocked then after checking the drain absolutely fine…he says the heating part is not working …. how can i rely on such fake commitments??? kindly rectify my issue soonest