What is the 90-day report process for an education visa in Thailand and what are the consequences of not complying?

Hi there everyone,

I would like to ask about the 90 days report.

Currently I am on an education visa since the end of January 2019. The first time when I extended in April, they didnt ask any report just stamped. I was there at the IO yesterday (July) to extend the final 2 months left from the visa. They didnt ask me to pay 2000 baht fine for the past, only reminded me to do it this month. So basically my questions are, why they asking me after 6 months (i obviously spent more than 90 days here) to report 90 days? They didnt fine me, so that can mean they dont care in reality? Whats happening if I dont do it again? The police will come and get me? If they were forget it last time, if i report now that means i have to pay 2000 baht for the past? What is basically the 90 day report? They want to know where i am living? If yes, what is the difference between the TM30 and this report? My address didnt change (i got successfully registered with TM30) Is that true first time I cannot report online only by person? I am very tired of this complicated system so If i have a chance I dont want to go there by person again. To be honest I didnt know anything about this report until yesterday. When you are feeling relax little bit there is always something coming up.

By the way, I will leave Thailand at the end of September for a longer time. (Not visa run)

Sorry for making this post a little bit confused, but theres really nobody else i can ask these questions and I am quite confused too.

Thank you for reading and have a nice day.