Using API OF GPT-3.5-turbo but billing cost from GPT-4

i am using API of GPT 3.5 turbo but billing cost was from GPT-4. how it is possible.
plz let me know if any one have faced the same problem before.
and also guide me if i have done something wrong that i need to fix.

You likely used some scam extension, website, or software, that stole your key and emptied your account.

Tell me where you found this software or site so I can go kick some a**.

Do not give your API keys out.

did u find any solution? because i am also facing this issue.

i contacted the GPT help center. they told me that your key was stolen. key was hard coded than and now i put my key on firebase firestore database. there is still risk of theft but minimum. also you can change key whenever needed.