This letter complains to an online service that they have billed you incorrectly.
1234, Main Street
Boston, MA 02123
01 April, 2005
<Recipient Address Goes Here>
I became a customer of <company name> <time you became a customer>, and have had no problems with your <Internet/online> service. However, I recently <method of billing> and found a charge of <charge> for <billing period>, which is much higher than normal.
I suspect that this bill may be in error. I have not used your service any more than in past months, and there seems to be no reason for this excessive charge. Please have someone from your Collections department contact me as soon as possible to resolve this situation.
Thank you for your time.
encl: <List of enclosed items goes here>