I thought this one is worth mentioning and I wonder how much money is accumulated by credit card companies from others in a similar situation.

After switching my webhosting service, I cancelled my account with the old hosting company about 6 month ago. They said all is good and my account will be closed when my term is up and no further credit card charges will be applied.

By accident only I checked my credit card account at Capital One which I haven't used for about 1 year now and discovered a charge from my old hosting company, which assured me no further charges to my credit card.

I called them up and they said they are sorry about the charge and will issue a full refund.

I just checked my account at CapitalOne again and found that the hosting company did not refund the full charge. They refunded everything but $5.32. Enough for CapitalOne to charge me a past due fee of $15.

I called CapitalOne unfortunately it was their way or the highway.

I went ahead and send a message to CapitalOne through my account page with the following content:

" To whom it may concern,

a company falsely charged my accoun $390.80. They apologized and promised to refunding the full amount. For some reason they refunded only $385.48. Now, for a balance of $5.32 you charge me a past due fee of $15. I have initiated a transfer of the balance including your past due fee and my commitment to you ends with this. 

I am officially requesting the closing of this account with you. 

Your services are no longer required, you are fired :) ...

Without a doubt you got the christmas spirit going. So on that note,
Merry Christmas and a Happy New Year to CapitalOne!"

Update:

I called the hosting company again and asked them why they didn't refund the full amount which they initially agreed on. They then said they didn't find any record of me ever having requested to close the account and refunded the pro rate only. I wasn't in the mood to argue since you never go anywhere. I wonder how they retrieved the information the first time around after apologizing and promising the full refund :) and now suffered unexpected long-term memory loss.