How Long...

If you call a company to come out for regular maintenance work on a heating/CAC unit .. how long do you give them to call you back (or after how many messages) before you start shopping around for another company???

What if this company was the company who did the installation on both units .. do you give them more or less leeway??

if they installed the system I suppose I'd prefer them to maintain it, but I wouldn't call more than twice.

Like am470 said, it's a hard question to answer, it's very subjective.