It must be local infrastructure that's the problem. As my main provider, I've had Fibertel over the last 7 years, except when I had Arnet out in Garin for about 2 years (so Fibertel for about 5 years total - and Arnet was horrible out there!). I've had the Fibertel 10 mbps service for about 2-3 years now I reckon (don't really remember exactly when I got it).
I used to despise Fibertel but have tried Arnet (had it exclusively in Garin because it was the only provider, and once in Retiro) and Speedy (have only had here right at the border between Retiro and Recoleta) as backups and never got any better from them. In fact, I have Speedy as a backup now because that's what the owners of my current apartment used previously and I just continued paying for it so I'd have a backup. I let the girls use Speedy for their cell phones and other mobile devices so they don't screw up my bandwidth. Problem is, Speedy here in Recoleta is down about 20-30% of the time (guessing based on complaints from the girls, not actually noted). I cancelled Arrnet in Retiro because it really, really sucked, about 4 years ago.
I've had almost no downtime that I've noticed on Fibertel for at least couple of years but I've lived in Retiro/Recoleta for the last 5 years. Some years ago (maybe 3-4?) I had outages just about every day (usually in the afternoon) over a period of a month or two, which was probably when they were upgrading infrastructure.
I never expect to actually get 10 mbps, but right now doing a speed test (on Fibertel - Speedy is down

), I got 9.2 mbps down, 1.92 upload on local servers. Tried one in Austin, Tx and 7.5 down and 1.6 up (ping of 185 ms). Another in New York I got 8 down and and 1.8 up (ping of 163 ms).
I tend to have something playing all the time as I work and when it's NetFlix I almost never have any buffering going on except the usual buffering NetFlix does ahead of the current spot. I.e., I very, very rarely get interrupted and have to re-buffer.
As far as discounts and such, per the original question, I only have gotten credits on my bill when I called up and complained about specific incidents of downtime which never amounted to much. never really got put on a promo to make me happier, but then again I haven't had to complain for quite some time so not even sure how things are customer-service-wise any more.