What are the current requirements and costs for obtaining a retirement visa extension in Thailand, specifically regarding bank statements?

Went to Hua Hin Immigration yesterday to do my retirement extension. I use the regular income method from my super pension and transfer from oz as needed. First went to Blueport weeks ago and told I needed Thai bank statement (not Aust) so I went to Kasikhornbank and got a full statement for 14 months (200baht)

New immigration office is a bit of a nightmare compared to old. Old queuing system not installed. Had to sit with Officer just inside door who "checked" all documents and eventually gave me a number. Place was full of waiting people at 3.30pm

After about 30 minutes my number was called. Officer looked at my statement which showed the deposits which exceeded the amount required per month each month. He consulted a fellow officer and then the boss and told me I needed a further statement from Kasikhornbank International that showed details of the international transfers. Said it could take 2 weeks.

Headed straight to Kasikhornbank with a handwritten note of requirement. Was going good as girl charged me 100 baht for a letter then when gf arrived and explained again what she had been told (and I assume was written on the paper in thai) I was advised a statement from Kasikhornbank International would cost 1500 baht (yes 1500 baht as K had recently raised it's fee for this service) and indeed could take 2 weeks (although I was promised it in I week)

This appears the new requirement as at Immigration I was shown another applicants statement as an example (no privacy in Thailand 😏)

Will be interested to here costs of other banks for this service.