Just sent my refund now. I wonder how much he ended up getting back?
Well, the address has received:
https://blockchain.info/address/1Jt35Ww1GjM9iGyTM8mAyBmCPPdPz7Z35A0.00910939
0.012
0.01034493
0.00782222
0.00833241
0.01636022
0.05
0.007
0.01211514
0.4
0.24946551
0.00078327
0.13003489
0.00785308
0.03835116
0.01000602
Total: 0.96957824
So, about 5% refunded, assuming all payments are refund payments.