If you are currently in Canada with TRV, you have a UCI number written on your visitor record attached to your passport. The reason I am assuming you are in Canada is that the 800 toll free number is only valid within Canada.
While the recording asks for it, just wait and follow the prompts. You'll be able to speak with a representative even without a Client ID. The UCI number (universal client ID) would help them look up an application if you did have one in process.