Gold bars do not expire , they are owned in your game. The community can not deal with gold bar issues so you would need to contact customer support so they can look into your issue. Is a strange amount of bars to go missing
Your Gold bars will remain unchanged if you have a Game Account active or unless you use them. However if you let me know your game Id then I can contact our team to know the real reason.
Would ask you to edit your email out of the post as this is your personnel information and could be open to abuse. Click the cog wheel top right of post and edit