Hi, today I spoke with a representative via Facebook about this and was given a case ID as well. We went through several troubleshooting steps, but none of them worked and thus I was directed to come here.
Before changing my number, I had no issues sending/receiving texts and calls, but now when I try to place a call, I am told by an automated voice message, "Sprint has connected you to an external operator" and to purchase some sort of prepaid card. I just recently paid my bill (around the 16th) so I know it isn't that. I also am able to use my mobile data to browse the web without Wi-Fi, oddly enough, so to me this is more of an issue related to the actual phone number. It is almost as if I have no phone number at all because I had someone try to call both my old and my new number to no avail. I should mention I paid my bill, then changed my number later that day.
To note, I just recently moved states and my new number has the area code to reflect that, but I doubt it is related. It seems as if I am stuck in a weird loophole. My phone (a Samsung Galaxy S8) has had a message in my notification bar that says "requests are processing", but that has been there for almost 2 days now (ever since I changed my number).
Again, the representative and I went through all of the update and reset steps.