Just to add what Kool Breeze said about going to the police station. Check if you can get a copy of the report you filed just in case you don't have one already. I don't know if they give you a copy or not. It could be in your favour that you are genuine. To add to what Nigel Rustage said, please don't forget that the police have started with face recognition technology while they patrol at random and I guess they will be more vigilant over the pre and post New Year day celebrations. Just take care till you can make amends on Tuesday.
unfortunately with the law here (or laws anywhere, I guess) when in Rome do as the Romans do. Let me share a little anecdote here. Twice when I returned to Canada from short holidays abroad, I have only a small trolley bag that can be carried as hand luggage in the aircraft. on both occasions I was sent to the RED Customes channel for getting it checked. Needless to say I spent hours in the queue (others had tons of baggage) and even the Customs officer on both occasions asked me why I was sent there. I told them they have to check with the lady who sent me here. Now what do I do! I just had to comply though it was absurd to be sent to RED channel right?
With all the advice given here I think you still don't get it. Paying the fine is mandatory no matter what else you want to do to continue living here and even if you don't want to live here, you can't leave Thailand without paying the fine for overstay or face legal action for overstay as pointed out by others
Just remember one thing..... Branches of the same bank follow their own rules. I tried so many banks when I was BKK but now luck about an easy process. KTB was just across the road but it was a no no. One day I went to the mall at Rama 4, I think and all i needed was to show my passport. One SCB bank just asked me for another id apart from my passport. Luckily I had my Canadian driving license and it was accepted. account opened in few minutes.
Believe me Wise (Transferwise) is the best way to transfer. I have been using it for years. Not only do they give the best exchange rate, but they also charge the least fees. You can go and check it out and check with the other methods you use and compare. Also their fees are linked to the method you use to pay. I use direct debit because it is the least. They used to have transfer to only a bank account so if i sent money to someone who didn't have a bank account i had to use Western Union but their exchange rate is much less and fees high like CAD6.50. But now WISE has transfer to an e-walltet and there's a load of options but the most popular is GCash. Try them out will never regret it. and if you find a cheaper option I am ready to try it out too hahaha
I am a retiree here in Thailand but i have never taken the risk to have a one way and at Toronto airport I have always been asked to show my return ticket. So what i did was to cancel my return ticket the first time and now when I visit any other place i just buy a return ticket from BKK to the other country and back. saves all hassels