Your SW sounds like my AirTran. They are last choice. I will fly AirTran if they are a lot cheaper but I go in with LOW expectations. (Flew them last week... every low expectation was met. Check in agents, rude! They were planning a night out and could not be bothered to check in customers. Tried to charge me for luggage when I had booked via SW, big drama scene when I said no lots of sighing and complaining by agent! Flight delayed on departure, on landing we sat on the ground in Orange County for 40 minutes with no explanation, lost luggage! An hour flight took 2.5 by the time they finished. I could have driven LOL!)
I have had a few bad experiences on all of them so I tend not to let one bad flight throw me off. AirTran is consistently bad, but I keep holding out hope that SW will fix them instead of them ruining SW