Weekly Duty reward bug

I have not yet cleared Alexander - The Breath of the Creator (Savage), A10S, for this week. When I was in a party by using party finder and trying to enter the raid, it says I already received the reward, which doesn't make sense at all. I have never received any rewards because I have never cleared it this week. I wasted my time and was so pissed. Please fix this problem as soon as possible so that I can clear it for this week's reward.

Have you been into 11 or 12?

If you dipped a toe into A11S or A12S before you cleared A10S for the week, you forfeited your week's reward. The game does tell you this.