What should i do about a lying cousin ?

ok i have a couson angela , shes 14 !!!! i only get to see her once a week cause shes always with her friends !! and that only time is at church on wed !! so i always get exited to see her !! shes older than me !! just a little bit !! but sometimes she says shes comeing than she never shows up !! so on sat r church was going to a diff one and she said she was !! i got there and she wasnt ! so i txted her saying your a lier and i dont have time to be disapponted all the time ! she said well i never said i wasent ! so she said i was b******* alot and no its the truth !! what should i say to her ???