HMRC wrong direct debit amount

Advise please.
We had made an agreement with HMRC to pay our VAT bill over 4 months due to the value. Unfortunately the full amount was taken on the first agreed payment date.
This has caused us a big issue.
Is there anyway of this money being returned to us?
I have tried to speak to someone yesterday and have had varying responses, from its was us who set the amount up, to there was never an agreement in place, even though i have a letter from HMRC stating there was.
I look forward to hearing from you.
Ron

When you agree a "time to pay" agreement with HMRC, a direct debit is set up to take the agreed monthly payments over the agreed number of months....but if you also have a direct debit set up to usually pay your VAT return liability, then that will still exist, in addition to any time to pay agreement direct debit.
Usually when you have a time to pay agreement, you are meant to cancel any other existing direct debits for VAT and then reinstate that direct debit once the time to pay is finished.
You need to call debt management Payment problems and explain the problem.
HMRC should be able to credit the funds back to you under the direct debit guarantee, else speak to your bank because the direct debit guarantee matters and means if an error has been made, the funds will be pulled back from HMRC.
But speak with HMRC first, as regardless of who's fault this is, you had an agreement in place that has not been fulfilled properly. .

Hi Ron Lees
If you have an agreement in place then this would have been with the Time To Pay Team.
Please contact the appropriate helpline available at Payment problems or the phone number held on any correspondence urgently.
Thank you Jay for assisting Ron Lees with your helpful answer. I have created the live hyperlink in your post.
Thank you