Don Quxiote - I'm sorry to hear that. I have never had a problem with taxis here. I don't speak much Spanish & I'm very non-Argentine looking (blonde, blue eyed, fair-skinned) so everyone is quite aware I'm a tourista. In fact, I was in a taxi the other day & the driver missed the street. He stopped the meter & drove me back around, apologizing for the delay.
I guess my point is that not all Argentines are out to take advantage of you. Sometimes reading this forum, it seems all people do is complain about being here & how terrible everyone is & how everyone takes advantage of them. I would hate to see that become your attitude as well b/c of one negative experience.
Sure - there are people here who do. But by & large, my experiences in traveling here & now living here have been overwhelming positive ones & 99% of the people have gone out of their way to help me.