>The problem IS businesses refusing cash.

They legally cannot, at least not in the USA, and I doubt in most countries. Thanks to the legal tender laws, businesses cannot legally refuse the legal tender, especially in its cash form. Once a deal is made and cash is offered, service must be rendered or it is considered stolen. A fun way to exploit this (before coin machines) was to go to tow truck lots, offer pennies, and then report grand theft auto to the local sheriff when they refused.