No service at all

I ordered a sauna from Saunazone in October 2015. I immediately paid the full amount to ensure a speedy installation. What a mistake!!! The installation was postponed several times due to no stock.....I was ensured that they have sufficient stock when I ordered, After several months they said that they can install a much bigger sauna than what I ordered but then we share the additional cost. I received a number of different costings and I end up paying to much. I have been struggling for the past 2 months to recover the additional money I paid. After numerous requests I threatened to sue them and I was actually threatened by the Sales person, Dominique, that they will take legal action against me. I have never experienced such unprofessional service and behaviour, it is quite shocking.