Why my coins disappear?

Today, in the morning I have coins about 30 and I spend 8 coins in the noon for crystal box in the map. Unfortunately, in the evening I found I have only one coin????

Plz check my ID(alower) why my coin disappear?

Thx a lot.

[support7]

Dear alower,
Please contact your support in game via menu>help>support, to get this issue solved.
Thank you

Sincerely,
Haypi support.