I have had that problem for years but finally found a solution that works for me. I finally spent the extra money to purchase IMONEX coin acceptors to stop fighting the Canadian coins, other companies tokens that would jamn the machines. The service calls are too just too expensive. Customers often do not really know what is in there pockets as they just reach in and put the coin in the machine. A positive that has happened is I now get 40 to 70 dollars a week in quarters in the places I only take tokens so the switch will pay for itself sooner and with less service calls I am also saving time and money.