What I'd rather do if the ISP is the ones blocking my access to the favourite gambling website that I would always love to visit and play is to try another ISP. If still the same, I would try another unit or another mobile.
If that's really the case, then there's nothing much the OP can do but to use VPN. It's most unfortunate If that specific gambling website prohibits the use of VPN. You might not want to risk lossing your money for breaking TOS.

That's kinda frustrating though.