Keys Disappearing! :(

[815910_1452549902]

Several days ago, I bought 48 keys from the marketplace. I cant remember the exact date. However, as of today. I only have one key. I know for a fact, I didnt not use them. Ive been running dreadtide arena non stop. Ive done nothing else with my char in game, up to this point. I dont know whats causing it, but the keys are disappearing out of my inventory.

[ShakaAlek]

Did you open the chest in the arena?

[glkazama]

Chests uses Keys.

[Kicker93]

I rest my case :)