Can't upgrade my phone online - why?

I had this issue when I went to upgrade wife's apple watch.  I did call the customer service number, in which they did help me get the new watch and got it to me next day at no extra charge.  However, the guy that I was talking to said he would fix this issue and here it is a year later, I am having the same issue when trying to upgrade to the S22 ultra.  I really don't want to call them again to try and get this fixed.  Still wondering why I can't do this.  I had no trouble with Verizon when I upgraded online.