Someone has calculated the first 100 Trillion digits of pi, so if I understand the equation you're suggesting they means it is possible to know if pi contains all permutations of all phone numbers.

Yep, it definitely means we're above the average chance we could find a given 10-digit number in what's been looked at so far, if we're up to 14 digits! But here's the trouble: that calculation gives the "average" chance.

In the same way you could see the number "1" more than once in pi, you could see "11" more than once in pi, and so on for all sizes of patterns, as long as they're part of a larger not-yet-seen pattern (and as long as mathematicians' as-of-yet unproven guesses about pi are accurate). So if you're unlucky, even if pi does turn out to contain all numbers, we still may not have hit exactly your number yet, because larger patterns have been ahead of it that include things that aren't your number. But the odds are in your favor as far as I know.