Has Snapchat been banned on my iPhone?

Snapchat can ban your account for violation of their terms of service. In that case, you need to contact SnapChat support. Snap Inc is an independent company and has nothing to do with Apple.

See -> https://support.snapchat.com/en-US/a/locked

If you were banned by Snapchat it has nothing to do with Apple.

Apple has nothing to do with Snapchat accounts.

You will need to contact Snapchat.

Apple has not banned Snapchat on any of its devices and it is available for download in the App Store.

I hope i helped you!