Does IAH EcoPark tow if I stay past my reserved time?

Our return flights got delayed and we're coming back a day later than expected. Our parking (EcoPark JFK) is going to expire at 6:00 PM today. I tried calling them and emailing them but their office doesn't open until tomorrow. Just want to make sure I'm not going to get towed tonight. I couldn't find a way to extend the booking online, so I'm assuming they'll just have me pay the difference when we exit?