I'm trying to register the azure free trial. But after input the payment information. It prompt me that, the registration is failed. The webpage ask me to contact the support. When I check my credit card, 1 USD has been charged. But the account is not working as well. What should I do now?

hi,

Thanks for posting!
Base on my experience, this 1$ is  just for verification purpose, if you could receive this message, it proved your credit card and phone number is right. And from the tip message, I suggest you contact support via this phone channel http://support.microsoft.com/gp/customer-service-phone-numbers?wa=wsignin1.0 .

Or if it doesn't work, I would like to suggest you to try the one that mentioned by Tabrez at:  http://social.msdn.microsoft.com/Forums/en-US/7a2acffb-6419-4a3d-8fb4-c8258790a2bb/why-cant-i-sign-up-for-the-1month-free-trial
[quote]
Contact support here:   https://support.microsoft.com/oas/?prid=14238.
-tm
[/quote]
Please try it.
Regards,