Free sample offers how do they work

Im very new to swagbucks. Been swagging for about a week but im getting very discouraged by not getting credit for the offers i "think" ive completed. not to mention the surveys i'm not getting credit for. i'm ready to place blame on myself maybe i'm doing it wrong. anyone have any basic tips for how to get the most out of the free offers? i've read that i should stay away from the Lifescripts how true are the rumors that they are scams?