Hi ameira3,
We've noticed that you have continued using third-party apps, so we have locked your account. You can unlock your account by changing your password. But if we find that you go back to using third-party apps after unlocking your account, we will permanently lock your account. We regret taking that action, but it's a matter of safety: Using third-party applications can compromise your account.
Please note that your account will be permanently locked if you use third-party apps, even if you switch devices.
For more information, or to unlock your account, please visit:
https://www.snapchat.com/locked
Thanks,
Team Snapchat