Unlocked samsung s7 flash with T moblie filmware

[Bazzaboy09]

I have a USA T mobile s7 that I had to flash because it wasn't updating,(i live in uk). Now this phone was unlocked to use any sim. but the problem is that Vodaphone has said that can give me wifi calling settings because where I live it is just on the border of bad reception. But after flashing I now have all the t mobile stuff coming up on my phone that i don't want and the wifi calling still isn't working because i think it has to do with being T mobile firmware. Does anyone know the best firmware to use other than the one i used to get around this?