Any and every company uses maintenance as a selling point. How's this for a thought?
1 The drain pans look like crap.
2. The coils are filthy.
3. The condensers are flaking.
4. There are oil leaks all over the unit. yah di, ya di yah.
The other company never did a thing for you thats why your equipment runs like crap.

Soooo, How come the lowly refrigerator at home 99.99999% of the time gives you cold beer at your becon call, with 20 years of crap on the condenser coil. The only time the dirt disappears is when mama speaks those dreaded words. "Its time for a new fridge."
Kinda takes maintenance to a new level. LOL