If it doesn't find one, it's probably because there are none, so you would need to go to a busier place that has phones, e.g. a big phone shop.
They will receive it and be confused. If you can find out who they are, it's even better as you can comment on the by changing the 'nice ass' contact to the colour of their clothes or looks etc. or even send them a photo of themself via bluetooth.
This 'service' is a free and can be made confidential as well.