It is not possible for the government to prevent Bitcoin transactions by censoring the internet. With VPNs and web-proxies being easily available, that will be unpractical. So the only option left is to block internet altogether. It is never going to happen, as there will be widespread anarchy and chaos.
I agree with that there will be a lot of chaos if bitcoin is prohibited as an alternative means of transactions by the government even if the government can also block the internet network of people using bitcoin then everyone will protest about it that happens only anarchy.