Customer service? They probably don't have any call center that speaks Polish. They won't slap a .country domain if they can't deliver something up to their standards and not just allow people to buy and then have to speak in English if there's any issue with the product or delivery.

When amazon really commits to a country they put a decent amount of effort into it. In France for example you can quickly get someone over the phone to deal with your issues and they speak French.