Rev me- fee charged?!


My flatmate used Rev-me to transfer over money for bills, and she’s been charged 1.5%. She is from Slovakia and was sending me euros from her euro debit card. Asked a live agent, she said that it was because it was a Maestro card. Now, she linked me the faq,but there was no fee schedule for that. Can someone explain? Kinda annoying that it was hidden. First time she wasn’t charged, now when sending only 30 instead of 200eur she was charged. Why?