United States Senator Richard Blumenthal of Connecticut is encouraging United Parcel Service, Inc (NYSE:UPS) to refund the shipping charges to some customers who did not receive their packages on Christmas.

In a statement, Sen Blumenthal said he was disappointed after learning that many customers in Connecticut and across the country who expects that the gifts they purchased during the holidays would arrive on time for Christmas, but left empty-handed.

“In a very real sense, Christmas is on the line. I call on UPS to do the right thing and provide refunds to people whose Christmases were a little less cheery as a result of their late deliveries,” said Sen. Blumenthal.

The lawmaker added that he recognizes the tremendous work of the employees of United Parcel Service Inc (NYSE:UPS), United States Postal Services (USPS) and FedEx Corporation (NYSE:FDX) this time of the year as they put “grueling, long hours delivering gifts. Blumenthal said, “We are all grateful for their efforts.”

United Parcel Services Inc (NYSE:UPS) and FedEx Corporation (NYSE:FDX) failed to deliver packages on time for Christmas due to poor weather conditions and the volume capacity of shipments exceeded expectations. The two companies did not provide the exact number of delayed packages for Christmas, but tried to complete all deliveries on Thursday.

Natalie Godwin, spokesperson fof United Parcel Service, Inc (NYSE:UPS) said, “We apologize that our customers did not receive their packages on Christmas. UPS will honor its peak shipment commitments” to customers who used the company’s air delivery service.

A related report from Bloomberg indicated that UPS will refund all air and international shipments placed during the peak season, but no refunds for ground shipments. The company said there is no guarantee for ground orders places after December 11.

On the other hand, Scott Fiedler, spokesperson for FedEx Corporation (NYSE:FDX) said the company processed 275 million shipments between Thanksgiving and Christmas, and “very few” were not delivered on time.

“Our 300,000 team members delivered outstanding service during this holiday season, and we experienced no major service disruptions in the week before Christmas despite heavy volume. Every single package is important to us, and we will continue to work directly with customers to address any isolated incidents,” according to the written statement from FedEx spokeswoman Parul Bajaj.

Meanwhile, Amazon.com Inc (NYSE:AMZN) is offering refunds on delivery charges or $20 gift cards to some of its customers who did not receive their packages on Christmas. However, the e-commerce giant blamed the shipping companies for the delay, and pointed out that its fulfillment centers processed the orders of customers in time for the holiday delivery. The company is also reviewing the performance of the shipping companies.