Can not start phone with correct info

Hello,

I have a S7 and I know my password to gmail but it still will not allow me to get in. I rebooted my phone because it had a android issue and the message was android not currently working. I had no phone for 3 weeks. This is ridiculous and Sprint Techs can not help me the restarted the phone and said I have the wrong gmail. It is not because I went on my S5 by the way work perfectly fine that one is with Verizon for work and I have the correct password I can log in and see the phone but can not connect it. Please someone help me Sprint just wants me to buy a new phone.