Are these text or image ads?
Text ads are more often than not approved by the system immediately. If they are not, it detected something it wants a human reviewer to see. There's normally an "ask for exception" check box. I believe if you don't check and submit, it will never be reviewed and that particular ad won't run.
The time will vary depending on how long the queue is as well as if you submit around weekends as they don't seem to work weekends. But normally, it's fairly quick, a day or two.
Image ads are ALL reviewed manually. Again, time depends on how many they have to do. I've seen up to a week for image ads. After that, I send them an email as a reminder and that seems to clear things up very quickly. I haven't had to do this in over a year.
If you used a voucher and not given billing information, why would they bother reviewing your ads? I say, submit your billing info. I'm not saying that's the reason but makes sense to me. I don't do work for clients if they haven't paid yet.
