Bharat Petroleum [BPCL] — service charges of mechanic in case of gas leakage complaint and so are parts price

Address:	Mumbai City, Maharashtra, 400014
Website:	www.ebharatgas.com

I want to know what is the mechanics service charge called from the bharat gas incase of a gas leakage complaint.. I had called for a mechanic and he has charged me 200 /-for a 3 stove burner gas service... He replaced some back valve of hose from where was the leakage.. He charged me 250/-extra for that replaced part... When i enquired in market the same part was available for 60/- only.. He just randomly removed a part from his bag and fixed it... N told me the cost is 250/-... No mrp of the part was mentioned anywhere it was not packed and no information about the cost of valve is printed on the bill as well. All other part price list is printed.. So i had to pay 200 for service + 250 for the part.. I want to know whether the cost that i was charged of both was genuine... How come the cost of part varied so much from market value?.. Pls reply asap