Been trying to book online at Delta.com with no success. This issue just started a month or so ago, and has continued since then. It doesn't matter what route or segment I select. I get through the entire booking process then hit "Pay" and this error is returned:

We're sorry, Rob. We are unable to process your request. Please call the SkyMiles Diamond Medallion line at 877-220-6888 for assistance. Customers outside of the 50 United States should contact the Delta Reservations Sales office for their country. #101727R

I have tried a different credit card, changing my password, and every browser known to man. I can log in as my wife on the SAME LAPTOP and the transaction goes through successfully.

I am, however, able to use my iOS app to buy tickets. This issue is solely on the web site. Has anyone else experienced something like this? Any help is appreciated!