So how do i figure out what hack is on my phone

[Geraldbmwe36]

So a while back me and my ex gf went into Verizon and she got us both phones. I got the Samsung galaxy s7 edge and she got the iPhone. Shortly after she decided she didn't want to be on the same phone plan and a bunch of bs so we went to Verizon. Cancelled out the plan and we both started our own plan . Time passed and stuff started coming out. She was able to receive all my texts emails calls etc. She pretty much had full control of my phone. I had no private life. Couldn't text my dad without her knowing I did. .She was 50 miles away. I wanna know how she did that .I called Verizon countless of times and they keep telling me there's no signs of hacking or anyone on the plan. So I'm not sure if it's a 3rd party or she's got actual control of the phone .and to make things worse. I went to trade it in for a new phone and plan and I couldn't. The phone is reported stolen. Did she mark my imei number as stolen .someone please explain what could of happened

 

[B. Diddy]

Welcome to Android Central! Did you ever share a Google Voice number? Is this just simple SMS, or are you using another messaging service like WhatsApp?

 

[Rukbat]

If it was her account and she reported your IMEI stolen, you couldn't have gotten the phone put on your account. Once it was on your account, she can't report it stolen - Verizon wouldn't accept the report unless you were there too.

And that would stop the phone from working at all. So it's nothing to do with that.