So....what do u do when a female friend calls TOO MUCH????????

Im a woman too by the way. So this is not a guy getting chased by a groupie type of situation! She calls me way to much and now i just want her to leave me alone, what do i do?? Im tired of her and i have been dealing with this for a long time now! It's like she has no life outside of dialing me....if im busy and tell her i'll call her back later instead she ALWAYS comes blowing me up! I stopped answering her calls for a week now hoping she would let me breathe but she still calls daily faithfully. Should i tell her she calls too much?? Help!