True (and I also wrote that it may not be possible) yet the OP says it's happening.

There is a Contacts syncing button in Snapchat. Check it out please

Instead of helping him you chose to be salty and even without a reason. Care to explain? So that I can be corrected.

While that may be not possible sometimes apps that are granted rights still have them even if we switch off the option. Try restarting your phone and / or deleting the app and reinstalling it. That way you'll see the questions about access again.