If a user is harassing you, being offensive, or breaking Snapchat's rules of conduct, you can report it. Your phone app does not provide access to this feature, you will need to go to the Snapchat website from a web browser.
Steps

Step 1. Go to Snapchat in your phone's web browser
You can use any of the available web browsers, such as Chrome or Safari, to access the Snapchat website.
- If you are on a computer, go to Snapchat support and go straight to 4e stage.

Step 2. Scroll down the page and select Community
The menu will expand.

Step 3. Click Security Center

Step 4. Tap Report a Security Issue

Step 5. Select Report a security concern

Step 6. Choose My Snapchat Account
A list of possibilities will appear.

Step 7. Select the option closest to your problem
The next question will vary depending on the option you have chosen. In most cases, Snapchat will recommend that you block the offending account.

Step 8. Click Yes under "Do you still need help?
". A form will appear allowing you to provide additional information about the problematic account.

Step 9. Complete your form
Provide your name and contact information, the username of the account you are reporting, and any other details that are requested of you.

Step 10. Check the box next to I am not a robot

Step 11. Press Send
Your report will be sent to the Snapchat Security Center. If the account is found to be in violation of Snapchat community rules, penalties will apply.