Argentina and Urugay used to be some of the largest suppliers of canned meat in the world. The packing plant in Fray Bentos, in Uruguay, is gigantic and it used to supply much of the British Empire.
But its closed now, for the same reason that there is no canned meat for sale in COTO- because nobody buys it anymore.
It was invented in the 1880s, more or less, when there was no common refridgerated storage.
Now that you can get fresh, frozen, and smoked meats almost everywhere on earth, canned meat is just not very popular- certainly not in Argentina, where fresh meat is available, pretty cheaply, everywhere.
The Koreans do love Spam, though. Pretty sure you could get that in Barrio Chino.
My guess is that in the provincias, far from the city, you will still find a few small general stores in the country that sell canned meat.