Using Telegram along side the iMessage on your iPhone? Well, to block someone on Telegram for iPhone do as follows, so you'll never get a message from that contact or number:
1. Open the Telegram app on your iPhone
2. Touch the Settings icon from the bottom bar
3. Go to the Privacy and Security settings
4. Under the Privacy settings, tap the Blocked Users option
5. Tap the Add New option to start blocking users by adding them to the block list on Telegram for iPhone.
Tip: To Unblock a contact on Telegram for iPhone, go to the Blocked Users option (step 4), tap the person who is already blocked, scroll down and hit the Unblock User button.
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