Venedig Erleben: Geführte Walking Tour durch Geschichte und Geheimnisse

I questioned the meet up point 6hs before the tour, they confirmed it to be over at the airport (witch was €18.00 each way) I waited for someone to turn up and no one did. Contacted headout they said it was there, got me to try and contact a phone number, just played music. 15 mins after the tour was started ( that I wasn't at) I got the boat bk, on the way bk headout said that I had to verify my ticket at the kiosk and they would tell me the meet up point. Headout said they done nothing wrong but on good will would credit me half off the ticket price. Last time booking anything through Headout. Bad experience and unprofessional