Escort keeping numbers

[lapd]

Sorry if this is wrong place (mods will you move it ?)

Anyway why would escorts keep numbers on phone,I called someone months back she advertised Westmeath but I was passing through Mullingar not near Athlone, now every time she is in Mullingar I get text(very explicit) and I have never even met the girl!! but she obviously has my number and thinks I live in Mullingar, got text yesterday am I am not even in Europe let alone Mullingar!!.
Now if this girl was arrested or god forbid anything happened to her!, my number is on her phone and god knows how many more,so very easy to track phone owner(even if not registered).
So question is why store number? Makes no sense at all unless I was stalking her or something,or she had bad experience with me before,but I never met this girl!!