[Blackwood]

If im not mistaken you cant, id depends on how the issuer programmed the POS, saw an article on this somewhere, visually same pos in a different store might work just fine, its the company that proceses the transaction sets the rules. Cant remember on top of my head but somewhere by the cash there should be a set of stickers, visa, mc, etc on one of those stickers should have the name of the processing company, remember which one it was and stay away from it.
Most likely that shop got raped already so they got switched to pin on both insert and swipe so i suggest you stay away from it