@lychee And Paypal is especially notorious for this.
@codewiz Things that involve banking / finance / tax declaration I understand a *bit* more.
But when it comes to syncing contacts and calendar events between devices - then it's absurd to not let you change.
My domain name provider does the same. I have an account from when I lived in the UK and they say the only way I can change is to create a new account on their .eu domain and transfer all the domains across.