Phone numbers are easy - just take the modulus x of each digit, where x is a value chosen by you.

For example, using x=3 you would add 3 to each digit, if the total is more than 10, take 10 away from it (a bit like spinning the numbered wheels on a lock)

so:

Escort's number 0 7 1 2 3 4 5 6 7 8 9

Mod 3 3 0 4 5 6 7 8 9 0 1 2

or if you want to keep it looking like a phone number just start from the 3rd digit:

Escort's number 0 7 1 2 3 4 5 6 7 8 9

Mod 3 0 7 4 5 6 7 8 9 0 1 2

The point about this scheme is that's it's easy to remember so you don't have to faff about splitting, combining, reversing etc. etc.

Of course if you're unlucky enough for the new number to belong to an escort as well, then the gods really hate you