NetBet Casino - Removed my balance prior to completion of wagering requirement

I receieved an email stating that if I was to deposit in Netbet casino, I would receive a 100% deposit match. I proceeded to deposit £75 the same night and my deposit was not matched. I searched everywhere for a 'live chat' button, I phoned them and held for at least half an hour (3rd in the queue the entire time). I finally emailed them to request my bonus at 20.30pm 24/07/16 and didn't receive a response until 17.56pm 25/07/16 to tell me that I could now claim my bonus from the cashier.
I checked the wagering requirements and found I had £3000 to wager before I could withdraw. My balance reached £1012 and I checked my wagering requirements remaining and saw that the playthrough completion was only at 38%. So I upped my bet and kept spinning, the next time I checked my wagering requirement I was 81% of the way through. My balance stood at £595.53 and I still had £558.50 left to wager. I relaxed at this point as I knew that whatever I would make from her on in would be profit. I then clicked back into Koi Princess and my balance read £3.46.
I logged out of the casino and logged back in and my funds had just completely disappeared.
I phoned Netbet up again to no avail and I messaged them at 00.09am 25/07/16 to ask where my funds had disappeared to. I received no response.
I messaged them a second time at 20.58pm 26/07/16 basically informing them that if I didn't get an explanation as to the disappearance of my funds then I would be taking this complaint further. I also requested a copy of my betting history.
I received a response at 22.05pm 26/07/16 telling me that I had clicked to cancel the active bonus from the cashier.
Now I am a member of in excess of 50 casino's. It is the deposit bonus' that entices me and I make it my business to read all the Terms and Conditions of every bonus I take on. I know full well that to cancel a bonus will invalidate any winnings. So tell me.... with a balance of £595.93 (81% through a wagering requirement) who in their right mind would cancel it to leave them with a balance of £3.46?
I believe this was an internal job. They knew that very soon I would be placing a withdrawal so they removed my balance as a preventatative measure. I do not believe that Netbet are wiling to resolve this by crediting my account with my actual balance so i'm asking Askgamblers to get involved on my behalf. It's very frustrating when your account balance disappears and you find that the 24/7 professional customer service that you sign up to is actually non-existant. Hopefully my experience will be a warning to others.