Part of the service you receive from Time etc as a freelance Virtual Assistant is that you don't have to spend any of your time account managing your clients or dealing with their billing or payment queries. We take care of all account management and billing queries for you.
If your client emails you with a billing or account management query we recommend that you reply to the client copying us in at happiness@timeetc.com - we'll pick up the conversation and provide assistance to the client, leaving you free to focus on billable work.