I don’t think the telco would care, the contract is valid, they cannot resell the phone.
What you can do is ask her either pay it herself (change to her name) or ask for the phone back. If she refuses to do both, let her know that it is your property, and that you can make a police report against her for theft. If she is not fazed, then go ahead and make that police report.
You can at best case scenario retrieve the phone back (with all the accessories and box if possible) and resell it to pay for the penalty. You may not recover everything, but it’s better than nothing. You can also ask if you can cancel her sim card and use the line for your own. You may not get the phone back, but at least you can make use of the line somehow (hotspot or sth).
Been a while since I was on here, irl tings :pepecringe:
By the way, where do we go to see updates on lemmy functionalities? As it is, it’s kinda hard to expand, UI is incredibly hard to get used to. Plus no emojis, no gifs. Even BB forums got those like 23 years ago. Can’t even provide image url to display need to upload? :O