Is this wrong?

So about 3 months ago, I let a couple of my friends open phones on my account. I know this was a bad idea, but it's not the point of this post. Anyways, the first month they paid it no problem. However, during the second month my husband and I switched carriers. There was a lot of hassle with this because there were 5 people on my previous account that weren't all going to the same company. When it was all said and done with, my friends decided to tell me that they couldn't pay their bill because they had lost their jobs 2 weeks prior. Well I was pretty upset at this because it was $220 plus another months bill was about to come out. I told them I needed their phones back and that's when they informed me that one of the phones had gotten broke. Well that was $740 on top of the $440. I decided instead of returning the other phone, I would sell it to pay at least their bill so that we could close everything and I would pay off the phones when my taxes come in. None of the money from selling the phone will be going to me, it is going straight to the phone bill. My "friends" think I should return the phone to them so that they can sell it and only give me half of the bill. Is it wrong that I'm not giving it back to them?