What do I need to renew my retirement visa in Thailand if I have over 1 million baht income but less than 800,000 baht in the bank?

Sorry if these questions have been asked before.

I used to do my retirement renewal myself.

Then it just got to be a pain.

So started using agents, But they seem to have gotten very greedy

I have an income of over 1 million bt a year,

I do not have 8 hundred thousand in the bank.

But I was told by the bank they could give me a printout of the last year that shows I bring the required amount every month

To be sure will immigrations accept this?

And do I need anything more other than the paperwork that I have picked up?

I was thinking of going to do a trial run at the immigration office soon I have until June 13th.

I bought a house last year with my girlfriend

I am in Chiang Mai

Don't know why this stuff makes me so nervous

This will be my 16th renewal.

I try to book an appointment but none is available

So how does the queue work do you still have to be there at dawn?

Thanks for help