The parents, grandparents, cousins and widow of nine of the 12 people killed released a letter Wednesday sent to the theater's owner, Cinemark.
In the letter to Cinemark, victims' family members write, "Our family members will never be on this earth with us again and a movie ticket and some token words from people who didn't care enough to reach out to us, nor respond when we reached out to them to talk, is appalling."
The Plano, Texas-based company has been renovating the Aurora theater and plans to re-open it Jan. 17.
The company had no immediate comment. The families said they were invited to an "evening of remembrance" followed by a movie.
Governor John Hickenlooper and Aurora Mayor Steve Hognan are expected to attend the re-opening ceremony.
An unknown number of families also said they planned to attend.
Related Story: Theater shooting victim plans on being at reopening
The Colorado Organization for Victim Assistance (COVA) helped Cinemark distribute the invitation.
Reached by phone Wednesday, COVA Executive Director Nancy Lewis had no comment.
See a copy of the invitation
They said the company's timing was "awful" in sending the invitations two days after Christmas.
"It's a blatant lack of respect, especially for the families who are grieving over the holidays," said Jessica Watts, cousin of Jonathan Blunk, who was killed in the shooting. "With the preliminary hearing coming up, we're going to see what happened to our loved ones. January will be a very traumatic time for each person affected in that theater."
Watts' cousin would have turned 27 on the same weekend the theater is re-opening, six months after the massacre.
She says Cinemark's invitation only adds to their pain.
"They're looking to boost their own ticket sales at the expense of 12 families who are heartbroken at a loss," Watts said.
Aurora Mayor Steve Hogan released the following statement Wednesday evening:
"The process of grieving and healing is long, painful and difficult. As we take steps to heal and move forward as a community, I expect people will experience a range of emotions. For some, the reopening of the theater might be painful, and for others, healing. That is why it is important for the victims and their families to have a choice whether or not they want to attend the reopening."
(KUSA-TV © 2013 Multimedia Holdings Corporation with The Associated Press)