Message "WA67208" from WhatsApp, how to delete it?

I received a message titled "WhatsApp WA67208".
It's red like a pin message, it says "WhatsApp internal use. You can safely delete this message" but I can't delete it in any way. Even pulling out the battery or unistalling WhatsApp removes it from the messages list.
Anyone can help me delete it?

Thank you,
Marty

Hello Marty, try checking your permissions for the app and make sure you save them all to "allow." Then see if you can delete it or it goes away.

I tried but got no result. The message looks like a BB pin message (it's red and if I disable the option to mark Pin message with color red, the message turns to black) and hasn't been received by the Whatsapp application but I have it in the mail app.