Had a similar hassle when my wife and I signed up.

My sister-in-law is retired marines and she helped us become members by providing us with her access number.  As far as we were concerned, we were eligible for membership.  We established a joint checking and savings account and my wife established a savings accounts as an individual so that we could jointly apply for a refi of our mortgage later this year.  After funding the accounts (very small about),  I received a call stating that based on my credit score I was invited to apply for a credit card.  The next day I was approved for the credit card.  (new Visa Signature)  A week later, we received the debit and credit cards.  Activated the debit cards. No problem.  Tried to activate the credit cards.  Received a message that I must call in.  They wanted to see a copy of my driver's license, SSN card, W-2's, pay stubs, and tax returns.  My first thought was this is just to much of a hassle but I quickly reminded myself of just how well this CU treated their customers with generous credit lines and options.  A true banking partner, once you have achieved full membership.   It took about a week to resolve but it was well worth it.

Hang in there.  Provide them what they requested.  It is WELL WORTH IT!