Whatsapp Community Announcement Group adding problem

Hello,

Anyone here familiar with Whatsapp Community function?

I been trying to add for a company 4000+ members contacts into Whatsapp Community Announcement Group.
We use Whatsapp Community Announcement Group because we want to avoid contacts from seeing each other.

The limit of Whatsapp Community Announcement Group is 2000 people at the moment.
But when i added up to 1257 contacts, it pop up stated 'You've added too many contacts to groups too quickly. Try again later.'

I tried to create new Whatsapp Coommunity Announcement Group 2, yet it still pop up the same error again.

Anyone knows how long does it need to wait before i can add contacts to group again when this message show up?
I had tried to wait 1 hour and 3 hours in between, yet still unavailable to add.

I tried to contact whatsapp customer service through app and email, yet it only just using Bot for both Chat and Email, which is totally useless and helpless.

Anyone here know the answer for this? Or at least how to contact real human from whatsapp helpline?
Thank you. ????
 

Windows / Chrome 113.0.0.0