Can we just confirm are you using QuickBooks Self Employed? Have you disconnected your bank account? If that is the case could you please reach out to us on either FaceBook or Twitter under the header QuickBooks UK.
If you could just advise the transactions in your account have disappeared and we will pick it up. We need to take some details from you and as this is a public forum it will redact any private information which we will need in order to see if we can retrieve those transactions.