When we checked in we were asked for local tax, 30.9 euros. Given 50 euros, only returned 10.10. That evening we asked for the invoice, it showed the number 30.9. We asked why only 10.1 was returned? The reason is that the invoice prints the daily tax, later when checking out the invoice will change to 39.9 euros. When we checked out we asked for the receipt, it turned out there was already an envelope containing the refund of the excess billing, because the invoice was still 30.9. We deliberately locked our suitcases, then we wrote down the number of the locked position, when we returned the number had changed, but they couldn't open it.