Now i try to receive allowance for working in Thailand and my company say yes after four years fighting but only for 25 working days in a year. I try to contact the "Thai Konsulat in Munic" if they accept also a guarantee instead of the 500.000 deposit but i receive no answere. I try also to talk to them via phone but it is impossible to receive someone on the phone. And the risk that they deny my visa as a workcation and loose money is too high. And when it happen they don't give you the reason. So i will give up now. Sorry for try to work in Thailand. I will wait now for my retirement.
Lesson learn: sometimes you win, sometimes you loose.