Message contact suggestions problem

When you try to write a new message to anyone, type a number in the title box and there will be lots of contact suggestions.

However in these suggestions there are lots of invalid numbers, these numbers can be removed one by one. This is fine, but there even has some group contacts which is obviously some spam/malicious message contacts, these spam group contact cannot even be deleted, only can be blocked. Although you can block it, these spam contacts still showing up. Is there any chance to clean these spam contacts or just ignore them anyway?