I am in the process of renewing my retirement visa using the monthly income method. Previously I got a letter from the UK embassy, which although expensive, worked well. 

This year I am using a combination of evidence from my UK bank account and my Thai account. I am well over the 720,000 baht total for the year. However, there is a snag - last June, I only sent 25,000 baht, and my agent says that it is likely my visa will be denied despite having deposited well over 65,000 baht for the other eleven months. Had I known in advance of the new rules I would never have allowed this to happen. Is there anything I can do to sort this?

Any thoughts on this, or suggestions, please. 

If you are applying using the monthly income into a Thai bank of 65,000 baht from overseas you may be okay if all the deposits are clearly from overseas, every month and since June all over 65,000. That is because there is supposed to be leniency on this new rule and deposits need not be for a full year, this year, but should  at least qualify from January this year. 

Edited February 6, 20197 yr by jacko45k

The 65k baht per month totals to 780k baht for a year on 720k baht.

Since the rules just started at the first of the year immigration has been told to be flexible.

One month low out of 12 should not be a problem. As long as you have had the 65k baht going into your account this year when you apply it should not be problem.