How long can you leave it before extending a non O based on being over 50 visa ? Is 2 weeks enough ?

I’ve went the 65k a month route but have an issue. Last June (month 1) I was blind so my wife moved the cash from the U.K. she made a mistake with exchange rates and only moved 64970 bht. She realized the next day so moved another £50 but I’ve noticed the £50 didn’t come through as an international payment. Used wise.

Over the past year I’ve had 2 ops, a cornea transplant and a heart attack and I’ve moved more than 2 mill bht in this time (I know it’s irrelevant towards visa) but hope it would be taken into consideration.

So as it’ll appear on my bank statement I’m 30 bht short for that first month.

What’s your views on this ?- down to whatever officer I get? Rules are rules ? Also is there anyway I can somehow trace the £50 back to show it was an international payment ?

I’ll be going to petchabun immigration, cheers