I can't add anything but support and another voice recommending you look for employment elsewhere. Mean time CYA...make sure your contacts can reach you directly.

Would be nice to think, once you've found another place, your boss will see how this colleague is in fact stealing as she cannot do her job without others input first...but unfortunately, that is more of a childlike response to perceived unfairness. The kid runs away, and the parents realize their responsibility etc and beg the child to return. Just doesn't happen. Or rarely happens in the work place. Besides, even if it DID happen, after the comment your boss made....would you ever consider returning to work (after finding another job) just because your boss finally fired the thieving colleague? Especially, as you've mentioned, the criteria used to absolve her of guilt, is equal to yours, yet....you're not a thief ... rather the injured party?

What will more likely happen, is after you find other employment, your boss will find someone to replace you (because you were so adamantly shut down when you suggested taking the phone directly) and the colleague will continue to steal from that person until that person wises up and then quits and so on and so on....the dynamic between your colleague and your boss is curious, to say the least.

At any rate...take care of yourself. Like S4ndm4n suggests, don't over cook the goose, but definitely start looking for other digs......and when you're ready to move on...do so. Without a snarly goodbye or dire warnings to your boss. It won't impress or change their mind, but it will lessen your worth to them.....keep your head up, march on...knowing, you were right and eventually....what goes around, comes around. I've never seen it fail.

Take care