I ordered over a dozen of parcels from them and everything was fine and cheap, however one item was defective so I returned it.
The discussion about the faulty item was handled quite slow (in my personal opinion), multiple people handled it, but a couple of phone calls speed it up significantly. Unfortunately, my complaint was "merged/misassigned" with a complain of some other guy/girl/company so a courier came to me twice to get the defected item, also they send me two ID of the issue that they raised for my complain in their system (ID that i should write on the parcel before shipping it back). Quite confusing.
They payed for shipping the faulty item back to them, I don't know if polish law obligates them to that, but that's OK.
Once the parcel was shipped back, they replaced the item and shipped it on their cost. That's OK.
I would still give them 10/10 because one can't find any cheaper&&reputable seller in Poland (I live here, they are from here) or in Europe or for some stuff even globally (as visible in this thread) and (in my experience) they don't intentionally make problems to take back faulty items on reclamation.