How did the phone have the details of a credit card you don't use on your phone? Every credit card added to the Wallet has to be manually authenticated, and also verified by the bank which involves emails or texts back to you, unless you activate an "add to wallet" feature within the bank's own app.
Thanks. I use my credit card for online purchases using my iMac but not my phone. So Apple obviously took the information about my card from my iMac and transferred it to my phone without my permission. I've written to complain but assumed they won't do anything. That's why I joined MacRumors so that I could publicise what they did and alert people. I also told Apple that I was going to warn others by writing to the Guardian