I have now heard from Platekompaniet. I bought from them last month (15 april), but then got an email the day after that they were very sorry but they sold more than they had, and that a new shipment would come in a month's time.
I had not heard from them since, so I asked them about this next shipment. They just responded today, that they do not know when they are getting more and that they hope it is in June. In other words, they just lied to me in the first mail a month ago about a new shipment so that I would not cancel my order.
Since they turned out to be completely unreliable twice (first in selling me something they didn't even have, and then in telling me they would supply it to me in a month), I will never do business with this company again. I suggest you also keep this in mind when considering to buy from them.