That's why I moved from BT
BT decided to charge me an extra £4.50 admin fee because I paid by card every month (and on always time) - they weren't happy unless I used DirectDebit.
So I moved to Skype for the majority of calls or use mobile free minutes. My quarterly bill (calls only) has dropped from ~£40 (+£4.50) to (literally) £0, mobile cost unchanged. Despite my initial complaint about the fee, I did try to thank BT afterwards for driving me to switch to Skype but all I found was a complaints section on their site so I sent it there instead, again I still didn't get a response.
I also pay bills slightly later now too to get my £4.50 worth of "admin charge", meaning I save interest on the £4.50 - bless BT for saving me ~£180 a year in call charges!!!