Published: Dec 25, 2013 5:36 PM EST
Updated: Dec 25, 2013 6:06 PM EST

CAPE CORAL, Fla. -- Thousands of people across the country had some empty stockings this Christmas. Presents should have arrived in time for the holiday, but didn't make it under the tree.
That's because UPS, the world's largest delivery service, says it was simply overwhelmed!

Amongst the new toys, games, and Christmas cheer sits an "I owe you" note to Carly Allison's mother. 

"We wrote a note and it just said we got you a Roku, we just stuck it in her stocking because she didn't have anything to open this morning. She was surprised when she got that," Allison said. 

The gift she ordered that was guaranteed to arrive in time for Christmas didn't make it. "It was guaranteed delivery for Monday night. And it didn't come. We had overnighted it."

She's one of thousands across the country feeling the same frustration. UPS blames a surge in e-commerce orders, as well as an ice storm in the south that hit as the shipping rush began.

In a statement, UPS says: 
UPS understands the importance of your holiday shipments. UPS is experiencing heavy holiday volume and making every effort to get packages to their destination; however, the volume of air packages in our system exceeded the capacity of our network immediately preceding Christmas so some shipments were delayed. UPS is not making pickups or deliveries on Christmas Day and will resume normally scheduled service on December 26.   

"We're Prime members. So we have a membership with Amazon that they give us 2 day shipping for free. We paid extra on top of our Prime membership to get it faster.  And it still didn't come. So that's disappointing. We'll kind of lose trust in UPS," said Allison. 

A UPS spokeswoman can't confirm how many of the packages have been delayed, but says they are nation-wide. "It would of been better if they had maybe sent us an e-mail saying hey, 'we're running behind, we're swamped. Your stuff is not going to be here.' But nothing. We just didnt get anything," Allison laughed.  "The Grinch came and took our stuff, I don't know!"

There may be one consolation. UPS says it will honor service guarantees for air and international deliveries, which may include refunds.