I was pretty darn sure what dish the installer supplied was up to them (as long as it was a dish network dish), but whatever. I wouldn't be too concerned about your age because welp, there's this thing we call age discrimination! Then again, I don't think that actually ever worked >_>
I'm 18 myself, and have been dealing with morons like that since I was 14 (computer repair people for my $7000 machine that was rather new and in warranty and needed new parts from time to time!!!) -- as a friend of mine said it's funny to see them go all "yes sir" and such after telling them off for being idiots when they're twice your age..
Erm, anyway -- it's worse with cable installers, even if the installer is only about 5 years older than you. Those morons! They try not to run ANYTHING anywhere if they can help it, after all they figure every bit of coax in your house is theirs for the using since "that's why it was put there"....
Cable on the lawn? Was it boxed? The first installer left a box/spool of vextra RG6 *drool* but I had no use for it (or so I thought) so I had the next person who came a few days later to fix the install go ahead and take that, wish I had it now >_<
That installer was a freak though. We had a light that needed new bulbs and was high up, he had a big ladder, we offered to pay him something if he would change the bulbs, I guess he was cool with that but then he ditched lol.
Felt kinda sorry till I saw the DP34 laying in our rain gutter the next morning..