Non-full payment

Hello, i'm new to booking. I had my first two orders, and still waiting for the payment to arrive (it has been more than 10 days sinc they said they sent it, I don't know who to contact), but what I don't understand, is that I should be paid 72 euros, and booking writes to me, that they have sent me 61.45 euros???? Could someone explain this to me please?