That message comes from the fact that I subscribe to Office and thus get something like 1 free hour of long distance from Microsoft, owners of Skype.
I also pay for the unlimited subscription, but even though I and others have complained about this silly issue, they steadfastly refuse to fix it. All they have to do is look at the fact that I have an unlimited subscription and use it first. No other free subscription is needed.
Morons … seriously. They invariably drop at least one call per month because they also do not have the competence to switch to the other plan in the middle of the call.
And yes, the call just dropped as I was writing this …sigh …