Whatsapp is an Internet application that uses mobile number for its registration.
Despite this application being used for communications, it is not related to Telcos, and is not part of Telco service offers.
If you find that someone has previously used your number to register for Whatsapp, you can reset that through Whatsapp.
Here's the possible steps
- Wait for the timeout
2. Click on Need help getting a code?
3. Click on Send SMS
The steps above are based on Whatsapp FAQ.
https://faq.whatsapp.com/1197347060992858/?cms_platform=android