Possible wrongful dismissal?

So I've worked at a retail shithole for about 3 years now. I've done really well, received many awards and recognition for my work. I gave my 2 weeks resignation exactly 1 week ago and was pulled into the office today only to be told they are 'terminating' my employment a week early without cause. Although they are paying me out for the remaining shifts i was scheduled are they really allowed to terminate me early without cause?? Personally I think they did that because their turnover rate is incredibly high and they don't want 'corporate' blaming it on them so they p it off to the little guys. Just wanted to know your thoughts.