I have just asked/contacted the seller of my Bitcoins for help.
The wallet.dat file will be mailed to them in a secure way and they will try to regain control over the Bitcoins.
If you haven't sent the wallet.dat file yet... DON'T!!! The wallet.dat file will be mailed to them in a secure way and they will try to regain control over the Bitcoins.
You should NEVER send your wallet.dat file to anyone, ever... That is literally like handing over a physical wallet full of money to someone. Unless that person is completely, 100% trusted then this is a VERY bad idea.
I hope you have not sent it yet... if you have, and the person you sent it to is not a close personal friend of yours and/or 100% fully trusted by you, you may as well kiss your bitcoins goodbye!
