I had the problem of my gold card being lost in the mail when my membership year renewed.

So, I asked Diamond Club to send me a letter by email stating that my Gold Card was arriving, and I printed the letter out. I also printed my most recent bmi statement. I had no problem getting into Red Carper Club in Chicago, Minneapolis, as well as the Maple Leave Lounge is LA and Vancouver. On the letter, there is a phone number for the lounge to call shall they have question regarding your membership status.

Hope this helps.