A Happy Ending
I read so many posts about bad experiences, that I thought I would post something good for a change:
I went to book a business flight to Europe today and tried to apply two of my 3 remaining global upgrade certs. It would only take one. I used the chat feature to ask what the issue was. They told me I had applied two of my three certs to flights to & from Tuscon this past March. I thought I had used regional certs, and told her that I had made a mistake and didnt intend on using global certs for regional travel. She asked for a few minutes to research. Upon return, she informed me that she had reinstated the two certs used by mistake, and I could apply them to the new ticket to Europe. I was surprised and impressed by her willingness to correct something that was my fault. I now have D1 seats for the price of PS. These little things make a huge difference and are why I remain a loyal Delta customer.