How to completely delete the contact and send me a text message with a different number, can I still receive it?

If the mobile phone number is deleted, but it is not in the address book, you can still receive calls and text messages normally, unless the mobile phone number is blacklisted to restrict communication.

You can add this person to the blacklist, and then you won't receive the message from him.

If you delete a friend from WeChat, you can't accept this message. When you delete friends from QQ, you can receive short messages, but you can't receive multimedia messages and files.