Virgil,
Two suggestions:
1. Try a former colleague. It's unlikely the phone girl will pass you on to a competitor, but everyone knows everyone in this world and if you approach a girl in the right manner (so she knows you're not a stalker, creep, or asshole) she's likely to at least pass a message onto "Olga." I often get text messages, "hey do you know a 'Carina' who worked at xxx?"
2. Give us guys more to work with. The photo is cool, but I have 14 "Olga's" in my address book. I'll bet there are 20 massageplanet readers who either know Olga or her best friend:
Most customers don't know the name of the places they frequent. What is the closest street intersection?how old is she? where is she from? (Russia, another former USSR country, ..)what personality?did she talk about working at other places at same time (its pretty common) or where she'd worked before?how many days a week did she work? did she usually work at same time as a specific girl? Good luck!