Warning with this company, I tried to book a fligh...

Warning with this company, I tried to book a flight, but guess what, they have sent me an email that my method payment has to be different way, that I have to do it asap in order to save my reservation, so I have sent them a e-Transfer right away, well I received another email from them that the price has changed and now I need to do an extra payment to keep my reservation. They think that they are smart and we are stupid...