Blacklisted because asked for reroll?

Hey guys!

I normally access steamgifts hourly, so I try to expend all my points joining giveaways.
Last weak I joined the same game twice (if I remember well), and as lucky I am I won both keys.
So I activated the first one and asked the second user to reroll.

Just because I asked for reroll he blacklisted me from his future giveaway... WTF?
Is this normal (I'm noob here in Steamgifts)?
I know the user is free to blacklist any user he wants. But in order to have a good relationship with everyone, I'd like to know how you guys behave in this situation. Should I just click "RECEIVED" and ignore the key (probably this is wrong according to rules)?

Thanks everyone!
PS: As soon as I'm not an english native speaker, probably there's a lot of mistakes in this text. Also, I'm still learning about culture in english speak countries so if this is a question of culture, I'd be very happy if someone could explain me how this works :)