What happens if you get approved and can't give T-Mobile the deposit right away?

[DBZmusicboy01]

Do they have to run a credit check again even if it's a week later?
And I heard some people below 600 got approved with ZERO deposit due ? How is that possible ? Choice of the seller or other reasons ?
Wanted to know why.

 

[DBZmusicboy01]

Like if they asked for $360 instead of $0 down.