Mottled, dirty, with contaminants and sites that look like mold and mouse droppings

I have received the speaker brackets rather quickly, but are 5 of the 6 brackets so heavily contaminated that I can not use it so. The 6th is also not really good but I can not accept. The impurities are not with a cloth and are apparently penetrated deep in plastic. The plastic is untreated and large pores, so no wonder. The impurities seen partly as a subject the parts on a moldy mat, other parts look like traces of mouse droppings in multiple holders always in the same place. So it seems to be happening during production.

Who has white boxes, should refrain from these cheap Haltern, look really not good.