"unpaid $400 + A 'stolen' Gift Phone = My Ex's New Hobby Threatening Police (ga/pa)"

In February 2026, my ex and I had a falling out and he moved out. I paid $1,000 to cover his move. Over text, we agreed he would pay me back $400 of that, and in exchange I would return a phone he had previously given me as a gift (I had been paying only the service/line costs on it, not the device itself).

He never paid the $400. It's now been about 6 months. I completely dropped it as I knew he was difficult and wouldn't pay it back so I tucked the phone in a drawer waiting for if he would pay. He out of the blue texted threatening to call the cops on me for 'theft'

A few relevant details:

Location: GA (where im Located) and PA (where I paid for my ex to move when he moved out)

• I have the original text conversation where I proposed the $400-for-phone exchange, and he agreed in his own words.
• The phone was originally given to me as a gift, with no conditions attached at the time.
• I live in Georgia; he lives in Pennsylvania.
• He has not paid any portion of the $400. and yet I paid more to mail more of his stuff he forgot to pack such as an art kit, a collectible menu, and a book. he realized that he has another book that here that he has left for 6 months and now is asked for that back as well.

My questions:

1. Since the phone was originally a gift, does he have any legal claim to it now, especially given he never followed through on the agreed payment?
2. Given the interstate situation, would police in either state actually have a basis to act on this, or is this a civil matter only?
3. Do I have a stronger claim against him for the unpaid $400 than he has against me for the phone?

Any insight into how courts typically treat "conditional return" agreements like this, or how interstate disputes like this usually shake out, or even if he has a claim that's worth standing due to the text agreements, would be helpful. Thanks.