"Yet it is wrong for a government to deny the people to access foreign services over the Internet when they want."

It would be wrong to deny access if there was no good reason to do so. However, if those foreign services are (a) harming citizens of a sovereign country and or (b) they act in ways that violate laws of that country then its government has every right to take action against said services, and one of the few means available is to block access to them.

As those services are outside the jurisdiction of the country it cannot take action to stop them other than to ban them from the country—they can do that because they have jurisdiction within their own country.

If a citizen of that country wishes to use those foreign (banned) services then he/she can do so as long as he/she moves outside the country to a jurisdiction where those foreign services are deemed to act in a legal manner.

Banning access to foreign services within the jurisdiction of a country is not the same as banning freedom of movement (to leave the country, etc.).

By you insisting that citizens ought to have a right to access foreign services from within their country would mean that you would automatically deny that country the right to protect its citizens from harm from that foreign service—for if everyone had access the government could not protect its citizens. QED! That's nonsense, that's not how the laws of countries work.

The other way of reading your point is that you consider that those foreign services cause no harm. There's solid evidence that these services are causing harm, it thus follows that a country has a right and a duty to protect its citizens therefrom.

The crux of this debate is about granularity—how much harm do these foreign services inflict on a country, and of course every country has a different value system which leads each to implement different rules.