Need Some Help!!! Badly!!!!!!!!!!!!!!!?

Ok me and my ex broke up over a yr ago and we becase good friends afterwards and we talked everyday until about 2 months ago I stopped talking to her. Well i wanted her sister to give her her stuff back for me cuz her sister and i are close. I gave here sister the stuff and she threw it away but what she told me was that she gave it to my ex and i know its not true cuz it took her a week to tell me and my ex would have certainly retaliated. Her sister doesnt want us talking, when we were together her sister kept asking me why am i with her, her sister told me to stop caring and worryin about my ex. She also told my ex to stop talking to me b4 all of this happened. Why would she throw away the stuff? My ex has a b/f so it shouldnt bother her that im giving the stuff back right? And her sister has a husband so its not like she wanted me. Can someon plzz explain whats goin on here.