I had not read that story by Urbaneja Achepol. So much good Venezuelan literature in my waiting list.
The tricky thing about back-scratching (another term for the message of the post I scratch your back, you cratch mine) is that is has been used for political purposes.
Populist politics have exploited this alleged rule according to which one must be thankful and repay accordingly. The most dramatic cases, in our country, have to do with all the social programs the government has created and that people have to repay with unconditional suppot for the regime. There have been documented cases of people who have been evicted from houses/apartments "given" to them as pat of the Gran Misión Vivienda because at some point the have protested or shown some critical attitude regarding the government's policies of incompetence.Great post, @nancibriti

Narcos have also instituted another way of showing gratitude for favors received. That's why they become likable criminals and are idolized in towns and regions where they show their generosity giving people food, money, jobs and other forms of generosity, in exchange of which they expect nothing less than abosolute loyalty and protection from authorities.

I think we should be thankful and show gratitude, but depending on who did us the favor we should be critical enough to even reject the favor (although in some cases, it is unfortunately impossible) or do the right thing when the moment comes, even if that means to "betray" those who once favored us, if they happen to be criminals.