Why does the SMS reminder function opened on the bank card hurt other people's mobile phones?

The subject asked why the SMS reminder function opened on the bank card was sent to other people's mobile phones for the following reasons:

1. Wrong mobile phone number: When filling in the bank card, the wrong mobile phone number was filled in, which caused the SMS reminder to be sent to someone else's mobile phone.

2. Banking system failure: There is a loophole or failure in the banking system, which leads to an error in sending SMS reminders.