Why, do best friends bomb u off then go all mardy with u and then when u hit them and they go all mad and angry and dont speak 2 u!! ?? heeelpp!!

i need help,, 1 ov my best friends is bombing off and now shes all mardy with us and blaming it on me :(.
i hate it,, i hit her with a racket 4 a laugh and now shes proper b****y about it and wont talk 2 me!! :(:(

any advice?? xx