contact matt through here: https://royals.ms/forum/forums/support.108/ and tell him in details with paypal transactions in it, its rare but happens sometimes.
If you have the payment transaction as completed, then you can enter it and copy the transaction ids if its happened several times. Just open in the forum i posted a thread and in details post your paypal email, your ign on which acc you trying to donate on and the transaction ids and matt will look into it whenever.