So how do you ACTUALLY create a Telegram account without leaking information ?

[Scottyzero]

This isn't a random question. I've actually done quite a few efforts to solve this question. It's one account per number only meaning services that let you receive SMS online/on-app aren't a solution and I actually bought a small phone with a pre-paid SIM card and, even after making sure it was activated ( And in a spot where I literally never went before, making sure to bring aluminum for when it was over to make sure there's be no way to trace it all back to me ) the phone just didn't receive the Telegram SMS, even after several attempts.
So what happened ? Has the ISP responsible for the SIM card blocked Telegram stuff ? Has Telegram blocked numbers they believe are from pre-paid SIM cards ? How do I even create an account on Telegram, now ? Any trick, even by PM ?