So, I received a new phone not too long ago. I activated without deactivating the old phone. I used the same phone number, but I've came under the assumption that someone else is using my old phone to read my texts and listen in on my phone calls. Is this possible? And what is the best way to go about fixing this if it is?
No, it is not possible. If you had an iPhone I've heard of iMessages being sent to a iPhone after it's been deactivated, but that's not how cloning works.
When you activated the new phone, the old phone should have been deactivated automatically. Only one phone can be active on a line. Was the old phone OFF when you activated the new phone? What did you do with the old phone? Where is it now?
I can attest for the longest time after I activated my TB, my Incredible did receive any messages also that came to my TB, I could not reply off the Inc, but it certainly did receive the messages