This was a GREAT thread! Great advice and some good humor to boot! Thanks FJ. I also have had no problems from people who make renting their business, even if it is just to rent to a few foreigners at a time. There are so many great, buena onda people in BA, but unfortunately a lot of the bad ones are found making estafa business with foreigners and hard-working Argentines.
It's good you got most of your deposit back, but I would say...that's not good enough. They caused you stress at the end of your trip, and you had to fight them just for some of your deposit back...and they would just as quickly do it to other foreigners. You should post their information, name, location of apartment if this doesn't get resolved fully.
DON'T feel pity for them because they are an old couple. SaraSara is right. Electricity costs nothing. It is heavily subsidized by the government. The novio freaked out about how high our bill was this month, too. Our BImonthly bill was 85 pesos (subsidized amount 113 pesos)...or about 12 dollars a month... and I used the washer and drier almost every other day. Our gas bill is less than 5 dollars every TWO months. If they felt they needed to charge more for their rental services, they had that opportunity from the get go and could have been open and honest with you and published what they thought was a fair price; instead they chose to be shady and bullying.
I think someone should start a thread LISTING the names and addresses of landlords, apartment owners, immobilarias who screwed them over. Obviously, this could be subject to abuse but internet users should be keen enough to distinguish posters who just signs up for an account to make a slam from regular BAexpat posters.