This letter demands a refund from a company for poor service, essentially selling you something based on a salesperson's explanation that it was right for you.
1234, Main Street
Boston, MA 02123
<Recipient Address Goes Here>
<time you purchased the product> I purchased <product purchased> from your company. I made the purchase based on the insistence of your sales staff that this <generic description> was exactly what I needed for my specific situation. I have since discovered that your staff was wrong. That being the case, I must insist on a refund of the full purchase price.
I feel that I was sold something that was not right for my needs simply to make a sale. This is not the kind of service I have come to expect from <company name>. Please let me know what action I need to take to receive a refund as soon as possible. I appreciate your attention in this matter. Thank you.
encl: <List of enclosed items goes here>