Like it says, you'd need to contact billing@railway.app from the email associated with your Railway account

I've already contact them with this mail. But they still say me this :
"Hey there!

Thanks for reaching out to Railway. This is an automated response acknowledging your message.

Kindly note that this mailbox is intended for billing enquiries only - we do not respond to other queries over this channel. Check out our docs for more information.

Thanks,
The Railway Team"

That is an automated reply telling you that they have received your email. From here you should just wait for a response from the team

So how many time should I wait ?

Hard to say, probably won't take too long though, either this week or early next week if I had to guess