Amazon Prime Account Locked for Verification — Can't Log In

I am an Amazon Prime customer in the USA and since this morning my account has been locked due to a verification request. When I try to log in and use my Prime benefits, I am unable to proceed because of this verification step and I cannot access my account at all. Until now, I have not been able to resolve the verification and I have not yet contacted customer service. I am dissatisfied that my Prime access has been blocked in this way without a clear and simple way to complete verification and continue using the service I am paying for. I request that my Amazon Prime account be unlocked immediately and that I be allowed to access all my Prime benefits again without unnecessary delay. I also expect clear guidance, if any further verification is absolutely required, so that my access is not interrupted in the future.