Non payment of winnings

hi,
hope you can help me . I joined netbet as a new customer on the 19/4/2014 placed a £50 wager and won ,I declined the bonus offer and withdrew £52 which left me £50 still in my account from which I placed another bet which won me £458 ,,the £52 was placed into my bank account and the £50 my first deposit taken from netbet from my account ,,But that's were the normality ends im afraid when I requested my £458 to be withdrawn it was accepted on the website and placed into what they call reimbursement in progress and that's were it still remains today .After talking to customer services they told me I had to send passport and bank card proof so I could be validated and then they would proceed to pay me my money owed I sent all documentation they asked for at the time and waited a day or two but still no progress I spoke again to them and they said I had been validated and it was in the hands of who ever processes payment's and waited again several days and emailed them to see why the delay got a email back refusing me again and now asking for bank statements and then they would pay me so on 2 occasions I have been told they would pay me and still I await i am with many bookmakers sites and never had a issue till now is it they don't have my money and delay tactics until they get the money or am i been stupid here i do have conversations on emails which i have sent kind regards mark