poor service took entire amount off my account when purchased

I have been trying to reach the company for two days now with no response. The feature is that you can pay over 3 months however when making the purchase it took all of the money off my account for the entire purchase. I need this to be reversed and split over 3 months yet no one can assist me. When I go on the chat it takes ages and I dont get a response. When I call in no one answers I sit on the line for almost an hour without response. I need urgent feedback