Not sure what they are selling

I received a call from a gentlemen claiming my mother filled in a survey. She gave him my number. He was calling me to give me a free holiday voucher. The only catch was that I had to share my holiday experience with my family and friends afterwards. His supervisor gave me a code to take with the next day to claim my prize. Both of them promised that no personal information was needed from me, that it wasn't a time share and there would be no presentation. I arrived at a small affice at a shopping centre where I was asked to fill in a form and was made to sit through a presentation. I left without a holiday voucher and only a promise that I would receive further details via email.