Amazon refuses to call me: Credit Card Invalid You must update your existing credit card information or add a new credit card to regain full access to this seller account

I am a new seller and I can’t get started selling until I have this issue resolved. Amazon charged my card $40 for the selling plan but I am still getting this message. I have scheduled call backs from Amazon on 10 different occasions and they won’t call back. I also get an “Internal error” whenever I try to request a call now. I’ve been at this for 24 hours now and it seems like it will never get resolved. I’ve bought thousands of dollars worth of inventory to ship to Amazon. Any help would be appreciated.