Verizon has apologized to customers who pre-ordered the iPhone Duo through the carrier but have since been informed that their delivery is delayed.

In an email sent to affected customers, Verizon said an "unexpected shipping delay" means that iPhone Duo deliveries to some customers will "take a little longer." To make up for the inconvenience, Verizon is offering affected customers a $100 Verizon gift card that can be used online or in-store toward bill payments or merchandise.

"We owe you an apology," said Verizon. "We appreciate your patience and the opportunity to make this right," the company added.

Verizon said customers will receive an email about the $100 gift card next week, and it assured that it is working to fulfill orders as soon as it can.

"Your order is secure, your place in line hasn't changed, and our team is actively tracking your shipment to get it to you as quickly as possible," said Verizon.

MacRumors reader Ryan showed us that he pre-ordered an iPhone Duo from Verizon when…