Advice wanted if possible 
So we were beginning to plan a 2020 wedding in Santorini through a Greek based planning service. We chose a package and chose a venue after being given the price list. We had reserved our date and paid a deposit to the planners to secure this, but a couple of weeks after paying the deposit (and being told the venue was closed) I was then told by my planner than there was a new price list for 2020 and the price of the venue has more than doubled!!
There is no way we can afford to pay this for the venue and there were no other venues on the island that the planner were prepared to work with that were what we wanted and within our budget. I have reached out to the planner and said that we aren't comfortable paying that much for a venue and want to withdraw but they are now refusing to give our deposit back.
I feel like we are within our rights to ask for a refund as we paid our deposit on the basis that the venue would cost x amount and the price has been raised since we agreed to it. I understand that it is the venue and not the planner who has put the price up but surely it was the planner's responsibility to check on our behalf that those prices were correct for the date we were asking?
I don't want to be brash and start threatening with taking legal action but I feel that we are totally justified in asking for a refund. Has anyone else had this problem before?
Thanks in advance xxx