[fdryer]

All I can ask you for now is where are the fuel pumps that are supposedly 'dead'? It would be interesting to see these 'failed' ones, if they are as you have every right to have the faulty ones shown to you. Any reputable shop would have no hesitation in showing you damaged parts.
The fuel sender unit is part of the fuel pump assembly. I suspect you may be dealing with a less than honest shop...............................