week long double exp suddenly show up in elixir buffs after today's update

[Onggo]

i don't have any idea whether if this a bug or not... but it shown in my elixir buff after today's free revive update...

i never bought this kind of elixir and not even found in my purchase history... and luckily my platinum were still in the same amount as yesterday...

is this a bug or reward??

if this thing is considered as a bug, i guess it's okay if it would be fixed soon or i can just let it vanished next week...

but, if this thing was a reward, i appreciate it, thank you... but, i guess it's a bit useless if it considered as reward... why give a week long double exp elixir to a character which already reached max level 71??

hmmm... bug... or reward??

my character in game name : Onggo