You have been incorrectly informed. 11 years ago I came to Thailand on a retirement visa from Australia. I lived here for a number of years on extensions of stay based on being over 50 years of age. A few years ago we purchased a home here and as a result when it was time to renew my extension I did not have the required 800,000 thb in the bank. So I successfully applied for an extension based on marriage. But the Immigration lady told me that I could not keep changing the reason for my extension and that in future I would have to continue applying for my extensions based on marriage. By the time my next extension was due my finances were in better shape and I applied for an extenion based on being over 50 years and it was approved.
I do not understand why you would pay in the first place. If pressures ask for a supervisor to assist. As it is you condoned this officers illegal conduct and let her off the hook to repeat her scam on other foreigners. Instead, you should have brought the matter to the attention of the senior officer of the office..