iMessage working on carrier disconnected phone with no wifi

[ohhokkayy]

I have an iphone 5s that I disconnected from Verizon about 2 months ago. I still use it for iMessage with my email through WIFI. There's no grey number anymore only my email is used to iMessage. Yesterday I was at school and my wifi was turned off but I was still receiving iMessages through Verizon LTE. I made sure to test this so I drove around to different spots and I was able to message my friends through LTE even though I don't have carrier service on this phone anymore. Does anyone know what might be allowing me to do this? I came to the conclusion that Verizon has already released my sim to another customer and somehow I'm able to send messages because of that. Should I do something about it? I'm only able to send iMessages i cannot access the web or send MMS.

 

[C DM]

Do you still have a Verizon SIM in the phone?

 

[ohhokkayy]

Yes I do I've never removed it