I'm not sure if I fully understand the issue - you returned but had the raise effect on you?
Or did you got a raise, declined it and then returned?

The only explantion I can think of right now is: Due to a slight lack - or simply an error on your side - you hit "return" instead of "accept raise" because the raises landed a tiny bit to late on you.
If thats not the case, I'd recommend reporting it as a bug in that section of the forum.