O2

I have just put my new sim in my new phone and it’s come up saying “ sim 1 not provisioned” It’s not letting me sign into my o2 either I’m rather confused 

I have upgraded my phone now, when I get it and set it up will the other contract just stop working after? Thanks

I have been an iphone customer for as long as I can remember, I’m currently looking at Samsung Galaxy s10, but I’ve got like 27 pound left to pay off my old contract (iphone), but it goes out by direct debit on a certain date, if I pay this earlier w...