Oh, brother. Anytime someone says they're available 24 hours a day, seven days a week that would be one huge red flag. The fact that the pictures, when you google them, are connected to russian escorts from Brooklyn to Bensonherst to Edinburgh is another flag. I'm not saying I know who's behind the ad, but the odds of them asking you for a credit card number first would be really, really high.
Why don't you call and see, then let us know. Just don't give them your c.c. number...