You might not exactly be owed a chance. But, at the same time, it was not fair of her to just drop the whole thing and hope it would go away - she should have called back and let your therapist know, if she really did know she didn't want to talk to you. And it certainly would be better of her to give you the chance to talk that you're trying to find - there's no malice in what you're after, and you're legitimately trying to improve your life and you hope it would improve hers. It's not as if you're trying to do something you shouldn't do, and you shouldn't feel any guilt for trying to resolve things.
If she denies you the opportunity to talk to her, it might help to take that as a sort of closure of its own. It might not be the way you wanted, but you can at least say it's done now. If that's ever going to change, you can leave the responsibility to her - you've done what you can. Of the two of you, you're the one making an effort to repair some damage. So if that's not going to happen, it's on her. So you can move on, knowing that what you've done in the last couple of weeks is the best you could in a difficult situation, even if you feel guilt for creating that situation in the first place (I don't know about that, so I can't say whether or not you should, but the point is that even if it's entirely your fault, you're learning and growing beyond the person who made that mistake, by seeking to make amends).
You've done the right thing in trying to resolve it, I think. It's possible that she wasn't doing the wrong thing by saying no - but that doesn't matter. Maybe she even did the right thing, too. It still doesn't matter. She's responsible for her own choices, just as you are for yours, and I think you made a good one. And, either way, letting the whole thing dangle was wrong of her, if she was that certain about what she really wanted.
EDIT: Also I forgot the reason I was posting here in the first place. The temperature is too damn high.