Selling a product they dont have experience in

I started the process of getting a waste water and backup water system on my property .The sales lady of Calcamite did a site visit and subsequently a proposal with the offer .I did have some specific needs that I wanted included .They delivered the systems and I had a qualified plumber install it for me .After installation I found that the pumps supp**** was extremely noisy and that one pump was actually not fit for purpose. I started complaining to the sales lady , her reaction was that they changed the one pump but she also informed me that this is the first time that they are doing this.<br> After complaining on a mail I received a short disrespectful mail from Mr.Tenfold saying he will replace them but that I must not deface the pumps (what reason I have to deface them is another question) .After that I received a mail from a Mr.Lemmer ,he had a different view saying that they could have been damaged and so on and so on very long winded looking for excuses .He was saying that it was custom build and that they had extra cost even more reason for concern meaning that they have not done this before .I am not sitting with an expensive noisy system that does not do the job as requeste