cpu wordpress problem with my hosting provider

I received this message from my hosting provider: "We've detected that your account has reached our resources limit as per our Excessive Resource Policy found within our Terms of Service. In order to prevent your account from causing issues to other customers and instead of suspending your service, we have been forced to block access to your website(s)"

-->>they are saying that it's my plugins on my multisite. I use wpmu plugins and some well known premium plugins.

Please help. is there someone at wpmu I can email one on one so I can send more specific information they sent me?