Hello my phone network ic is bad. I can’t make calls or use cellular data and my iPhone has been updated but still having the issue

Go to Settings/General/About and look at Modem Firmware. Is the entry blank? If it is you need to reinstall it by restoring the phone to factory settings, then restoring a backup. Back up the phone first, of course:

1. How to back up your iPhone, iPad, and iPod touch - Apple Support
2. Restore your iPhone, iPad, or iPod to factory settings - Apple Support - follow the instructions to restore using your computer, do not using Settings/General/Reset (which is not included in those instructions)
3. Restore your iPhone, iPad, or iPod touch from a backup - Apple Support

If the modem firmware DOES have a value you may have a hardware problem. The first step is what I just posted, but after that you need to contact Apple support using the Get Support link at the top of this page.

How do you know your network IC is bad? And which one, the cellular radio or the Wi-Fi/Bluetooth radio?

It would be helpful if you describe the symptoms rather than your diagnosis.

Use the Get Support link at the top of this page. As I already said in a previous post.

What did Apple support say when you contacted them?

Hi Genevievv__

Welcome to the Apple Community,

Where some of us do our best too help each other troubleshoot.

Apple support have articles online that may help.

If your iPhone won’t connect to a Wi-Fi network:

https://support.apple.com/en-us/HT204051

and

Resolve Wi-Fi and Bluetooth issues caused by wireless interference

https://support.apple.com/en-us/HT201542

Hope something here helps you solve the situation

or

If you need more help:

There is a "Get Support" link to Apple at top right on this discussion page.

That your phone shows No Service or Searching. That is a problem that they know how to deal with.