This letter expresses your displeasure at the services of a tour company that did not go the places you expected, had guides that didn't speak your language, etc.
1234, Main Street
Boston, MA 02123
01 April, 2005
<Recipient Address Goes Here>
<time you took tour> <travelers> took <kind of tour> through <agency name>. <I/We> <was/were> very dissatisfied with the quality of the tour, and would like to inform you of the problems.
I feel that the tour was badly misrepresented by <agency name>, and I think <I/We> <am/are> entitled to some sort of compensation, such as a partial refund. Please contact me as soon as possible to discuss how we may resolve this unpleasant situation.
Thank you for your attention to this matter.
encl: <List of enclosed items goes here>