Regarding sheets, cheating only if you came to pay overnight and said and showed your own suitable sheets.
Specifically at Planika every bed has sheets already on it and not those artificial ones. (so you got the sheets you paid for)
Probably you also mixed up that you slept in a room with over 6 beds and not on shared bunks. Planika has some larger rooms that are more comfortable and spacious and not counted as shared bunks. About 15 people fit in.