Iza bro. I was also conned my first phone, Nokia 2310, by two guys who used the same tactics of "ngoja hapo nikuje" before I knew it they had disappeared into thin air and I got to realise after like 10 minutes of waiting and they hadn't shown up!
l was conned exactly the same way u narrate your story. my laptop went and l travelled all along from Maasai Mara university Narok To Nairobi Nyamakima.