What she's doing is wrong. If she broke it off she shouldn't be sending mixed signals, which she is. As far as the gym membership? Screw her. If she doesn't want to pay for her half why should you foot the bill? As far as the Bon Jovi tickets its tough shit. Don't accept them and don't go with her. Accepting them would mean that you aren't all that angry at her, and going would allow her to perpetuate the false pretense that she will pick the relationship back up one day. She can just as easily take someone else. Don't continue to let her string you along. Once you are done getting your stuff don't contact her anymore and stop answering her calls. As long as you make it an option for her to "keep you available" by keeping in contact she will do so. She ended this relationship, so let it stay that way.
...one can be sure of nothing until it has already happened...