PSA: My Telegram account is no longer under my control. 

Not sure the person is malicious or if @koodo just handed over my number to someone else but don’t interact with @/Kuushoo on telegram.

I don’t even know why service providers abroad can’t just assign completely new numbers.

I'm sorry to hear about your situation. It's important to stay vigilant and take steps to secure your accounts. Contact your service provider to address this issue and consider enabling two-factor authentication for added security. Stay safe online!