Purchased iPhone 7+ from Apple Store and used on AT&T for several months. Ended my AT&T plan and was using voip calls for awhile. Decided to get cellular service again but saw Verizon had much better deal so went with their service. During service signup on their website, their compatability checker had me enter IMEI from iPhone 7+ and it said it wouldn't work on their network. So I purchased a new iPhone 7+ during the Verizon signup process and was going to trade in my original iPhone as part of the deal. So after using new iPhone 7+ on Verizon (all works well) I see some posts that make me now believe I could have activated new iPhone 7+ on Verizon and transferred the SIM card to my original iPhone. Is this the case? Would everything have worked? I have both phones in my hands right now as haven't sent in the original yet for trade in. I'd like to avoid taking the hit on cost of a new 7+ ! Paying a restocking fee is much preferred lol. Thx!