Can anyone tell me why there are 2 immigration offices in chiang khan? There seems to be one called Loei immigration and another called chiang khan?

I stay in Thai based on 90 days marriage visa now. I was going to apply 1 year visa and Loei immigration strictly advised me to put 400k deposit. However, I read in rules that I should prove at least 40k monthly income on thai bank account. I have an account in Krungsri and calculated my statement, so during last year I transferred nearly 460k in total. If I add f.e.30k this month (annual income will be over 480k) and apply next month will it be an option for visa to avoid 400k deposit?