Suspended phone but can still text me with number?

So, I split up with my husband and my daughter went with him and my son stayed with me. I asked for their phones back because I shouldn't have to pay their cell phones and installments every month. I don't mind her but him... no. It's been a horrible toxic mess, but that's another story. I was going to be nice and pay this one last month and I've been paying since September when he left. Anyway, he ended up stealing from me and so I was done. I suspended, blocked and reported his phone stolen and there hasn't been any activity since the 9th but I reported it the 11th. I thought they got new phones because he is texting me from the suspended number and it says his line is still active on the account. I'm so confused. Aren't stolen phones blacklisted? If I have to pay off his phone due to the contract. I don't want him to be able to use it. I shouldn't have to pay for this grown man. Is him being able to use his number and phone normal eventhough I reported it stolen? Thank you in advance!