nationa wide company selling damaged goods

Bought a oil pump from company mentioned above, fit the pump to the car by mcanic, oil pump, pumped the oil the wrong way out of the main seal, called them to report the damaged pump, they told me to return it to send to factory.. After messing me around for 2 week they told me I damaged the pump.. But it cudnt be because the first try pump the oil the wrong way.. The car hasn't moved an inch .. Due to the oil pump, costing me public transport and stress please help