ASK THE EXPERT: How Do I Report an Online Gaming Site that Really Got Me?

James Turner of Surrey, United Kingdom asks:

I have been playing an online game at getmegamiing.co.uk and after coming 2nd and first 3 and 2 months ago, I have not received my prizes of £50 and £100. How can I go about reporting this site for fraud? I have tried contacting them, but get no reply and despite them saying they will send the prize (months ago), I am still empty handed and have had no reply for over a month.