I am sure even though you THOUGHT you did a survey at the garden centre, all they wanted was your name and address and phone number so they could offer you this so-called free holiday.
You then find the free holiday mean flying out from Plymouth and flying back to Edinburgh, or that the dates are school time, or the holiday is free but the flights are �300.
These are all cons and in future I would decline to do one of the these surveys.
In these days of identity theft, giving out your personal information could be very dangerous in the long run, you dont know what they will do with your personal information or who they might sell or give it to.