new unlocked Verizon Galaxy S6 that is supposed to be compatible with T-Mobile and At&t

[AC Question]

I had T-Mobile set up my Galaxy S6 phone and I have had nothing but problems with it. The connectivity is barely there. When someone calls me and I try to return the call it puts a "11" in front of the number and it won't go through. Even if I go to my contact list and try to dial out it says "Call Ended" after it rings a couple of times. It says it's 3G at the top and I thought it was supposed to be 4G. I am constantly getting "SIM card is not from Verizon Wireless". I transferred my SIM card from my Galaxy S4. I can't get my pictures to go through on my texts...then don't find out until the next day. Shall I go on. Seriously, I don't know whether to put the SIM card back into my old Galaxy S4 and reset this new phone to factory settings and send it back. I've already spent two full afternoons at T-Mobile trying to get this kinks out. Also, they had a real hard time trying to get the phone to connect to the internet. Can anyone please help me with these issues?
I'd be forever grateful.
Thanks!!

 

[IAmSixNine]

Get a Tmobile phone, not a verizon phone hacked (unlocked) to work. That will solve your issues.

 

[justnivek]

I've made several posts about this exact matter, including trying to use the dial pad in a phone call ("press 9 to speak to an operator")

I eventually sold it on eBay and put up an extra $100 out of my pocket to get the factory unlocked version (G920i) and it was the best move I've ever made

what caused me to get rid of it was constantly having to put on airplane mode to to get the signal back