Had the same thing happen a couple of hours ago in a club comp. Same thing, didn't want it, didn't buy it, & after restarting the browser a couple of times, had to continue with it as I didn't know how to turn it off. Submitted an in game bug report to WGT via the right click, so waiting to hear.
And having played most of a round with it have to say that for me, it spoils my enjoyment of the game & I REALLY DON'T WANT IT...
Anyone know how to turn it off? (which I think is poss?)