HOUSTON -- They shelled out hundreds of dollars for new iPhones and now they say their phones are worthless. Houston consumers called Amy when their Apple iPhones just stopped working. They say Apple is not willing to replace them.

KPRC Local 2 investigative reporter Amy Davis is looking into the damage some are calling a design flaw.

Our cell phones take a pretty good beating. We drop them. Your kids may use yours as a teether. But the Apple customers we spoke with said all they did was take their new phones to the gym.

"I never would've bought a phone if I knew would ruin the first time I got it out at the gym," Stacie Keneker said.

"They sell all these accessories that you are supposed to be able to use at the gym to make it convenient," Lee Pittman complained.

  But "convenient" is the last word Pittman and Keneker said they'd use to describe their iPhone experience.

"I would like a phone that works," Keneker said, holding up her iPhone that constantly resets itself.

"This phone is worthless to me now. It's useless," said Pittman, whose iPhone will no longer let him make calls.

When their iPhones stopped working properly, both said Apple employees told them a moisture sensor on their devices had been tripped.

"It happens all the time," said Pittman, repeating what he said an Apple employee at the Willowbrook store told him.  "He said they have this issue all the time."

What happens? Apparently sweat happens.

Both Keneker and Pittman use their iPhones at the gym to listen to music or use the calorie counting fitness applications that actually come with the phone. They said Apple employees told them their sweaty palms are the likely culprit here.

"If this was going to be sensitive enough where you can't use it at the gym, why don't they have a cover there?" asked Pittman, pointing to the opening where the charger plugs into the iPhone.

When we called Apple a spokesperson e-mailed us this 28-page product information guide.

On page 10, the guide advises to "avoid getting moisture in openings."

By searching Google for "iPhone moisture," we discovered a lot of Apple customers are peeved at the product they said won't hold up in less than ideal conditions. 

"If the sweat from my hand will ruin it, I can only imagine what would happen if I left it in my car this summer," said Keneker.

We asked Apple if it planned any design changes or better warnings to buyers about the iPhone's sensitivity to moisture and humidity. They didn't answer that question.

The Apple spokesperson who e-mailed said she would have someone in customer support contact Pittman and Keneker. We will follow up and let you know if Apple does anything for them.