If the hubs are getting rejected means it is violating HUbpages TOS. Read the hubpages TOS and see where you are violating, fix it and then submit again. Without fixing the issue if you are submitting means you are bound to get rejected again and again.
It might be as simple as having pixalated photographs.
The initial moderation is done by automated software filters and so sometimes you might get frustrated if you apparently dont see any violation.
If you are convinced that you didn't violate anything, you can send a mail to email@example.com and wait till they respond.