I came to Taiwan in July with a regular entry visa. I was going to work. My employer took my passport, but the job didn't work out and I never received a work visa. I got my passport back with a 90 Day Single Entry visitor's visa issued in August, and with an entry stamp for September.It is also stamped "used". I now want to leave Taiwan. It should be okay because of it has been less than 90 days since that entry date, but does the stamp marked "used" cause problems?