No, nothing helped. Then, it was about an hour later, I tried again. It worked. So, I believe it may be something to do with your server load. But, then, again, I think the error message must be more clear. If I knew it was due to the load, I could...
I just get this message while I am trying to upgrade phone & plan online for this black friday deal. I logged in, upgrade device->chose Samsung A50-> choose the plan (your exclusive) -> then, there was a pop up saying I have an offer for $200 credit...