Deactivating phone number from iMessage when phone was a work phone and didn't sign out when left job

ji541 wrote:

I cannot get the old phone number to delete from iMessage. I had a work phone, put my apple id in it and forgot to sign out when I left job and turned the phone back in.

I did get signed in to icloud by calling previous employer and having them give me the code that came through on phone. But, I didn't realize that I would have the same issue with iMessage. So is there any way to simply get me phone number deactivated with iMessage without bugging previous employer again?

No.

You employer should've had you sign out of everything and erase the phone prior to you leaving.