You play world of warcraft and sometimes it wont let you play what do you do

It mainly matters on the type of problem. if you are suffering from login troubles check your password and account name. recently WoW has merged with www.battle.net so you must merge your account with a new (free) Battle.net account. instructions will follow on how to do this on the www.battle.net page. if you are suffering from connection issues:
A. Make sure your router is up to speed.
B. see your internet sponsor. (rcom, charter, etc)
Another option is if your account has been banned you will not be able to play. usually if your account is on trail Blizzard will send an email.

(How do i get my account banned?
some reasons can be if you are using illegal addons that help you "cheat" in the game. things like
Gold multiplyers
Bot modifiers
item modifiers
etc.
another way is by "power leveling" and WoW gold buying.
Power leveling- paying real money to have your character leveled
Gold buying- Buying virtual WoW gold with real money
By doing this you need to give that company not only real money but your account. info. most of the Maintnence blizzard does is because some of the companies use another persons account to mess up there. servers
its just better to not buy levels and gold.)
if none of this has been helpful in any way visit the sight below.
you will find a tab that says support. from there you can find Blizzard's email address.

http://www.blizzard.com/