Missing deposit/failure to honor my payment.

I made 6 separate deposits of 50 euro each on the 17th and early 18th of Mar. My account was only credited with 5 separate 50 euro and the 6th deposit was discarded. I have proven from my banking transactions that 6 separate withdraws for 50 euro each were taken from my bank and it's in black and white on their site that my transaction history shows only 5 and one discarded. They are refusing to refund my money and I am on their online chat service at least twice a day, it's a joke to them and they're making a fool of me. Their email support doesn't even respond to my emails, not one ounce of decency or respect. They took my money and won't give it back. Even the roof of deposits of sent in twice now have been accepted by them but they still won't refund. Their online chat will ask which bonus am I speaking about or that they can't see what I'm talking about and the list goes on, properly having fun with it. It's my money that I work very hard for and I want it back.