I found something:
It seems that satoshibox.com generate a kind of "exchange"-link for every file.
I tested it by creating a new file and entered a wallet:
The pay-address was different from the one I entered.
So I went back and checked the payment address from my file (13 BTC) and it was the same address than the address where currently my bitcoins are!
So what could be the reason that I'm not receiving my bitcoins? Could it be a blockchain problem? Is satoshibox.com using the blockchain.info API or other API's for exchange?
The amount is 13 bitcoins, sent at 18.11.2015 14:30 is this normal for this kind of value?
I really don't know what todo (contacted support, they asked for details, I gave them, since that no answers anymore)