I have known personally two different folks that got their gas cut off. Both here in Recoleta not far from where I live. One a single-structure house and the other a whole apartment building. Both were as a result of the new regulations related to gas fixtures, venting and such. The gas company came and shut down the gas without warning and then told the house and building owners what all they had to fix. Relatively expensive stuff. Then once they had everything fixed they had to pay the inspector a "fee" and also a fee of about the same size to the gas company.
It took my friend in his apartment (which he was renting) about 7 months before the gas came back on. He ended up moving temporarily into another place during the cold months. The owner of the apartment from whom he was renting accepted no rent and asked that my buddy pay the expenses to maintain the contract, which was probably more than fair.
My other friend, with the house, took more than a year to get the gas turned on. He was trying to avoid paying the extra "fee". He went out and bought an electric water heater and such to delay the inevitable, but it finally got too cold this winter to hold off more.
Nlarrucia, I think your friend's owner is being an ass. I don't recall right offhand what the "extraordinary" conditions clause that is in the contract, as Bradley mentions, is worded, but I believe your friend has rights, even if maybe that means he or she can leave the apartment without paying any penalties. If it's not in the contract your friend signed, look up the official long term contract defined by law (assuming your friend is in a long term contract) - your friend has those rights, by law, even if it wasn't in the contract he/she signed.
Being a lawyer doesn't really mean much, unless she's practicing and has enough contacts. I've watched my sister-in-law, who was the head cook at a restaurant owned by a lawyer (not practicing), get fired the day after she told him she was pregnant, and offered a measly 1000 pesos as severance. Once she initiated a lawsuit, he falsified a number of documents to make it look like she had stolen something (he was so stupid that he didn't even notice he'd left the dates of the transactions she'd supposedly been involved with as almost a month after he'd fired her!). Her lawyer laughs with her quite a bit about the stupidity this guy presents every time they go before the mediators and then the judge.