Sisaket Immigration

Good morning please can someone enlightened me.

A friend of mine went to days ago to extend his OA visa ,he got in UK.

He showed his proof of money, more than 800000 Baht , in his Thai banc account , the money is there over 3 month. All worked fine until the IO checked the bank book. He denied the extension because my friend doesn't have this bank account not over 1 year. I'm not sure that this is a requirement. He lives in Sisaket but now he thinks maybe to try some other immigration Surin or Ubon.

Was it just made up by the IO ?

Immigration Opening Hours on Saturdays , Sisaket and I heard Surin to. Not sure about the others in Thailand .