At the same time, if the customer had cancelled prior to the free trial period, there would be far less hangups with them accusing her of owing them money --she would owe them NO money, still being under the trial period. It would be difficult for Earthlink to make the excuse about being owed money.

Furthermore, (and I realize I came off a little harsh here, but it is true) we live in an age where if you do not document everything on your end when trying to resolve a dispute, or terminate a contract, that large corporations are likely to just claim (through either incompetence or malice) that they have no record of your call. Documentation is, time and time again, your only friend in this matter. And if you have ever dealt with a large ISP such as AOL or Earthlink, when things do drag out and you have little or no documentation, time is on their side, and they know it. Some companies like AOL have a clause that says they only owe you a maximum of 2-3 months worth of fees in the event that a billing mistake is made on their part (something I found out from personal experience over a decade ago). Remember also that the poor sods in the call center get raked over the coals when they lose accounts, and so creative incompetence ("losing" cancellation records) becomes very convenient, as miserable as this is.