Connection

I have updated my phone through the computer as it wouldn’t update to ios13.5 it took me two months to even update to this for two months i have not had calls or text and as you can imagine with this pandemic happening not being able to called my loved ones or receive calls or text has been horrific. The update has now been completed and my phone network still is not working what can I do it keeps saying update failed mobile network will not work but the phone says on settings it’s updated