My exboyfriend exgirlfriend keep on callin me wat should i do?

me n my x brake up he call me we been talk n but havent got back 2gether but now his ex keeps call n me block i try 2 ask him y he giv his ex my num he say he never even talk 2 his ex about me if that were true y does she kno my number i never met her b -4 how does she kno about me i know hes lying 4 n he lies n say he never tell nobody about me but his friend kno my name can yall tell me wat 2 do.