Hey there beverley109,
Thanks for reaching out to Apple Support Communities. I understand you’re receiving messages from a blocked contact. I’ll be happy to help.
If the contact is blocked but able to reach out to you, make sure your iPhone is up to date:
Update your iPhone, iPad, or iPod touch
Check for any carrier updates as well:
Update your carrier settings on your iPhone or iPad
Also, see if you have any filtering apps installed on your iPhone. If you do, remove those, restart your iPhone, and see if the issue is resolved:
Restart your iPhone
I hope this helps.