Who would enforce these "Retributions/punishment" if there is no government?
One of the main reasons governments sprout up is to maintain law & order. That's why people consent to be governed, so they aren't murdered or robbed at random (only murdered and robbed in accordance with the rules of the state). Every society has a social contract, and societies larger than a tribe or perhaps confederation of tribes have central government mainly to enforce the social contract. Really the state is a mechanism to consolidate violence: and successful states standardize and minimize violence with a code of laws. Violence goes from random and widespread, to rare and practiced only by state on those who break the social contract to a pre agreed upon degree which warrants the use of violence.
History is filled with violence because it's extremely successful, sadly. Man will always resort to it to accomplish goals unless they are dissuaded by the threat of violence returned unto them (and often resort to it in spite of that threat). There are no historical examples of the kind of society you lay out, at least that I'm aware of. I am not a professional historian.
In addition, what if there's a contract dispute. Contract Lawyers have been around since at least Ancient Greece. With no government, who settles disputes to determine if a contract was actually broken? Are there courts? Who administrates the courts?
So if we are talking about regular humans, it's completely unbelievable in my opinion. But you have other options.
Drugs that make humans follow contracts that everyone takes willingly (under fear of being exiled or killed) that force people to follow contracts --Though I have no scientific way to explain this, so the drug itself wouldn't be realistic. Speaking of science-free you could do magic. This could be a story about aliens, aliens living surrounded by humans whose minds work differently than ours. Finally, my favorite, give these people a different language, a "magical" language with words that meanings and consequence are physical certainties. Maybe it's 4-dimensional language that determines (and must be in accordance with) the future and past to be spoken. If I used this magical language to tell you I will go to the hill at 3 o clock, I must go to hill at 3 o clock: furthermore, it will be a specific hill at 3 o clock in the afternoon today and you will know all that without doubt. Again, not exactly realistic unfortunately --but fun.
Edit: Another answer mentions the Amish, but the fact is that Amish communities have a Mafia to punish those who break the social contract --such as steal, rape... Or at the very least are within the jurisdiction of law enforcement entities such as local sheriff departments.
Furthermore, and perhaps off topic, how does this society defend themselves from attack without a central government to maintain a military?