Best answer by stephenrand
As this is your first post, welcome to the Pure Planet community!
Your closing/opening readings have to be agreed by an industry regulator, nothing to do with Pure Planet, and that process can take up to six weeks. So you should not end up paying for energy twice, but in the interim you may have direct debits taken by both suppliers. Don't cancel your old direct debit, as that will enable any refund to be paid. You can contact them and ask for them to reduce it to a minimal amount in the meantime.
Did you send photos of your opening readings to Pure Planet? That should prevent any dispute about your readings.
Hope that helps