As this is your first post, welcome to the Pure Planet community! When you post here you are talking to your fellow customers not directly to Pure Planet.
Sorry to hear you are getting fed up about lack of contact numbers - but I don't think Pure Planet make any secret of the fact that they are an app-only company - and lots of your fellow customers prefer posting here and getting answers than hanging on the phone waiting for someone to answer. And it helps to keep the price down of course.
If you send in your meter reading before the date of your monthly statement, PP will always estimate for the missing day or two. If it worries you, just send in your meter reading on your statement day.
Hope that helps