Me too, when I was still actively gambling at duelbits, I used VPN most of the time. I did not win big too, my biggest withdrawal from duelbits was around $3000 and there was no issue at all.
Ooo still a pretty good amount nevertheless. May I ask if you were using a dedicated IP or was it simply a regular paid VPN? I've never gambled in duelbits yet but I'm guessing they're VPN friendly?