I'm not defending your friend and don't obviously know the ins and outs but I "dumped" a really amazing friend about 10 years ago. And it really wasn't her, it was all me.
I was going through some really terrible family stuff and I was programmed to push, rather than pull on those friends I really should have relied on.
We were godparents to each others children, attended really significant life events with each other, she was more like a sister than my actual sisters!!!
About 4 years ago something happened, not major, and she got in touch to send her best wishes. Slowly but surely we have started to communicate and now that I'm older (and can healthily reflect back) I feel sad for the friendship I rejected, we've missed out on so much. It's made me realise how wrong I have been and I'm now trying to start again, I'm hoping to feel strong enough in time to explain to her why I did what I did and apologise.
I guess what I'm saying is that we're only human, and yes, it hurts like hell. But it may be for reasons completely out of your control and may also not be a permanent loss