Changing VAT financial settings within Xero & outcomes

Our affiliate company DabApps Branding Ltd set up the VAT integration with Xero, with the VAT scheme set to ''accrual'', and the tax details as ''tax exclusive''. Having set up Direct Debit on the 3rd of August we assumed this would be enough time for the VAT submission to take place on 7th Aug (the deadline) and the DD to take the monies. However our HMRC VAT account informs us the amount is now overdue and increasing. After spending 3hrs on hold to HMRC, evidently cannot speak to anyone to confirm that the payment will be made by DD or not and do now want to make payment via another method in case it will. We are accruing charges by the day. We also need to change the VAT scheme to ''cash'', and the tax details for both sales and purchases to ''tax inclusive''. Are we able to do this once the payment has been made one way another - what are the steps to do this. I will have spent almost an entire day trying to find the answers to these simple questions by the time I post this message.

Hello
If your direct debit was set up on time the direct debit will collect 3 working days after the 7th.
If you do receive a late penalty you can appeal.
With regards changing to cash accounting, you can amend thisy, you do not need to notify HMRC.
Guidance regarding the scheme is here at section 3:
Starting to use the Cash Accounting Scheme

Thank you, that's helpful.