Hello,
When running services such as the CampaignService, your clientCustomerId must be set to a client level account, not a manager account. Please set this Id and see if you are getting anything back.
Please also note that when using our PHP client library, API calls must be made through the command line.
If you are still not seeing any campaigns after modifying these, please
reply privately to author your SOAP request and response. Instructions on how to enable logging can be found
here.
Regards,
Anthony
AdWords API Team