failure	case of sth not working - usterka, awaria
defective	means with a mistake or fault in it - wadliwy
packaging	the box or wrapping in which a product is - opakowanie
faulty	not working correcty or made correctly - wadliwy
retain	is to gather, collect - zachowywać, zatrzymać, gromadzić
refund	is when we get our money back for the product - zwrot pieniędzy
replacement	is when we get new product - wymiana, zastąpienie
defect	is a mistake or fault - defekt
fault	a feature of something that makes it less good - wada
damaged	harmed or spoiled - uszkodzony
shipping	is the synonym for dispatch - wysyłka
delivery	dostawa
go wrong	means that something goes not according to the plan - pójść źle, popsuć się
misunderstanding	a problem in communication - nieporozumienie
misunderstand	to understand incorrectly - źle coś zrozumieć
out of order	not working - niesprawny, uszkodzony, zepsuty
unreliable	sb on whom we cannot rely -niepewny, niesolidny
incompatible	sth that doesn't fit - niekompatybilny, niepasujący
sth is down	means that sth doesn't work, is damaged - coś nie działa
bug	a defect in the code of a computer program - błąd w systemie, robak