Let's say Mr. Joe Consumer buys a $10,000 item online and accidentally sends the bitcoins to the wrong receiving address. The Bitcoin Foundation could setup a call center and a toll free number (1-800-BTCBack) to handle these situations.
Transaction fees could be increased to cover any additional costs associated with this new Bitcoin security feature.
I thought this was in poor taste as a joke, but are you serious?
Try it with an alt (not one that I hold, please). I predict a death spiral to zero value within a few days.
Forcing a chargeback system on everyone is insane. There's nothing stopping a sender from contacting the recipient to request a refund if the situation warrants, same as with any cash purchase. But putting a 3rd party in control destroys most of what makes bitcoin special, sends transaction costs through the roof, and creates a great bunch of new opportunities for scamming at a time when scamming is what is hurting bitcoin the most.