Robert A. Piccus i did 30 years ago but nowaday i find driving car or bike very dangerous. note that in 30 yearsvi do have 2 case, a dog that damage the front car and a big plastic box the i got in the shield...
So its about 40.000 Bahts by months, far not enough if you cannot legally work, and in case of accidents or medical problem (ok its happen only to other!) you will be on a BIG trouble. Up to you.
you can try to present them the prove that you are REALLY retired with an official document legalized, get a lawyer in TH as you will need to see a juge.