Best friend was just using me?

well.. one day i got a prank call from my best friend and i knew it was her and it was about giving away free tickets for something i didnt even sign up for, the person kept calling me and giving me second chances for the tickets which ik wont happen cuz if it was real there ARE NO second chances and i checked the number and it was the same as my best friend's and i said that its her but she keeps denying it.. and we chatted on fb yesterday and i asked if it was her and she said "no y cant u trust me before i get my cousin to be blacking out on you and then she did a snaps finger** thing.. it was like a whole different side of her.. and later that night her cousin kept calling me and sent me a txt saying "leave her alone she doesnt like u and was just using u so dont come crawling back being her bff" and then i said ok.. and then she said "NO ITS NOT OK so leave her alone" and then i said" that im trying to b nice and i dont want to cause any trouble" and then she said "thats y no one likes u ok bi" and now idk wat to do.. if she is telling the truth that my friend was just usuing me.. idk.. wat should i do?