Girls, why would she do this?

My ex was taking a class and I checked out a textbook for her that she needed for it. I got dumped months ago and the class has ended since then. I tried asking for the book back after I got dumped but she claimed she’d return it. Over the the summer I got a lot of emails from the library demanding I return it, so she never returned it. I sent her a text a few weeks ago saying: “hello, hope you are well, I’ve noticed you haven’t returned the textbook, please do so at your earliest convenience”. This was the first time I’ve reached out to her since getting dumped. She still has not yet responded to that text. Can someone please tell me why she would still have the textbook, let alone ignore my message when I tried being polite about this? I just don’t understand why she’d do this especially when I didn’t do anything terrible towards her and returned her things asap.

Girls, why would she do this?
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