Iphone XS Max confusion

[O3]

Ive had an O2 contract since forever. Recently i upgraded from iphone 6splus to XS Max.

I have tried literally everything i can think of but for some reason it does not read the sim card. The phone says "No Sim" Absolutely no carrier details about o2 come up on the phone Iv'e tried multiple other sim cards including a pay as you go and it doesn't even pick those up.

Ive restarted and restored the phone countless times with and without the sim card, tried setting up the phone as new but nothing.

Am i doing something wrong? 

Please help It's stressing me right out

[MI5]

@O3 

Assuming you are inserting the sim correctly (it's upside down compared to the 6) then the phone must be faulty.

If you got it from O2 you need to contact then to exchange it.

https://www.o2.co.uk/help/phones-sims-and-devices/our-returns-policy