Kontrol S2 Mk1 remix sets question

Hi All. When i set up decks C and D as remix sets and load samples in i do not seem to have any option available to choose between 'Loop or Single shot .. i see it on some videos but cannot find the setting either in preferences or on the decks themselves.... when i load short samples into C or D they come up automatically as either a loop or a single hit..but there is no way to switch them over.....grateful for any help cheers