Girls? Please help!!!?

I have known this girl for a year. We go for drinks together. I am really good mates with her best friend. She has told me she enjoys my company but when I made my feelings known to her she said she wants to stay friends because I had planned to go back to South Africa soon. When I changed my plans to stay she didn't change her views. Whats going on?? She still phones me almost everyday. Yesterday we both used up about �10 quid each texting and talking to each other. I am really confused!!! Has anyone been through something similar because she is ripping my heart to shreds....