I strongly suggest that people read post number 17 before replying to this topic.

OP went to immigration already.

anywhere else they would have to honour the stamp and admit it was a mistake.but thailand i don,t think will see like that.i got a seat belt ticket a few years ago before it was 60 pound,the police had a old form with 30 on it,so he crossed out 30 and put 60 on it.a few weeks later i got a letter and gave me warning instead.they made a mistake and had to cancel it much to the copper that give me the ticket,he wanted me to pay.somehow you will not have the same luck in thailand