Original valve not delivered, refund needed

having tax invoice of company delivering us valve worth 96760 including gst, but its local and they don't provide test certificates. we initiate refund but they are not listening. also first they deliver faulty valve and we send it to company through same delivery as they know it is very urgent to deliver on time, we face heavy impact on face value from our customer. then they first take this faulty valve through courier then they send this valve second time but when we check it is not original also when we talk we only need test certificates of this valve in case this is original but they deny to send and also when we try to negotiate for refund they are not refunding valve money. everything is recorded on mail till time. till we send them mail concerning there first time valve is local make and used valve send to customer.