Why did you send a message to my dad's mobile phone when the mobile phone number of the bank card was changed?

This is the bank's fault. I have also encountered the situation that the bank sent text messages to both mobile phone numbers, but I really abandoned the original number directly, so there is no such trouble. The mobile phone number originally left in the bank is not easy to eliminate. The machine in their system has an automatic storage mechanism, so we can only ask the bank again and completely cancel that mobile phone number.