ee uk carrier vanished

iPhone 6 EE PAYG Carrier option vanished from settings menu phone constantly searching for network. I have put another EE SIM card in phone reset the network settings and restored the phone and updated software to iOS 11.2.1 nothing is working! I have also tried an O2 SIM card which wasn't accepted due to carrier so I think I'm locked to EE.

In general- settings- about-

Network - Not Available

Version- 11.2.1(15C153)

Carrier- EE 31.1

My wifi and Bluetooth are working fine.

In Settings- Mobile data menu

EE -

Wifi calling

Carrier services - contact EE 150 and ee.co.uk

Setup personal hotspot

Any advice would be much appreciated