I don't know what is this shit. Where can I find back my block reward?

[overdoignism]

(old deleted)

OK, Finally I understood what happened.

PC A, running my friend's wallet + farming.
PC B, running my wallet + farming.

Some day I went to remove PC B and merge my wallet into PC A,
And it's all OK,
His farm work correctly,
My farm work correctly,
Nothing conflicted, no warning, no error, no remind.

Until the pool tell me I got a block reward again (previous is on PC B),
And I found the reward was pay to my friend's wallet.

I don't know how to comment, what kind of flawed system is this?