Bad service

FNB offers bad service to clients, I’m constantly having network issues with the number, I ported my number and then realised it was a bad move , I ask that they let me go to my old service provider who offered best network n then give me a number to use on Thier cellphone but they refused so il literally being jailed with a number that doesn’t even belong to them it’s mtn number pls don’t bul**** me give my number back