There are charges added when using a calling card in your Resort room. Trust me, I have had it on my bill and questioned it many times!! It is either $3 or $4 per call.
As of about one year ago, Disney abolished their outgoing phone fee (it used to be $0.85 for local, or 1-800 calls.
When I stayed at AKL and BC in March, there was no charge for any local calls or 1-800 calls.
I also used my calling card, and had no fee added.