My $20 hit my account immediately. People having issues and not seeing it are most likely bundled accounts with AT&T. I never bundled my account because of all the issues with AT&T billing in the past.
Previous disputes, it takes the 1-2 billing cycles to show up for bundled accounts.
My account is through DIRECTV and not AT&T and it is not bundled with anything else and I got the credit applied to my account immediately.My account acts like it is bundled. They put me over on AT&T billing. But I am not bundled with anything.