Reliance Home Comfort installed my furnace on a Sunday, but the heat pump could not be finished until the following day due to a "rare" breaker they did not have with them (the "rare" breaker was actually available at a big box hardware store 5 mins from my house). They promised to come back the next day to finish.
Long story short, I emailed/called the sales rep and called their customer service many times over the next 10 days.
On day 10 someone finally called, even though I was promised that someone would call after each time I reached out.
As for the installation, it was finally completed after 12 days!
Be very careful with Reliance Home Comfort, you are only important until you sign the contract.