Whatsapp — fake account

I got a call as they are calling for sim verification and first i ignored and again they called and told just tell the 6 digits which is sent to your phone for verification or else it will block the sim. So told the 6 digit no. After that my watzap is not working. So i uninstalled my whatsap and reinstalled again. So i don't know if there is any fake account created by using my mobile no. If it so what i will do.