One high school graduate's party was ruined by a plastic foam cake covered in frosting and decorations, according to Houston TV station KPRC.

Marsy Flores, the graduate's mother, told the TV station that a Houston-area Walmart gave her a graduation cake made out of plastic foam for her daughter's special day after first failing to prepare a two-tier cake.

The store offered her another, smaller cake free of charge, Flores said, to make up for the initial mistake.

All was well until Flores went for a slice during the graduation party, when she realized that underneath the requested vanilla frosting and a customized picture of her daughter was a sheet of foam.

“They can't replace the moment that we lost," Flores told the station. "It’s a special moment, and this is what we got for it, a Styrofoam cake. Not only did they mess up one time, they did it twice."

Nellie Flores, who identified herself on Facebook as Marsy Flores' sister, posted a video on the social media platform last Friday of Marsy tearing through the cake to reveal its plastic foam interior.

The family received a $60 gift card from Walmart after the incident, Marsy told KPRC.

"We apologize for our mistake," a Walmart spokesperson wrote in a statement to USA TODAY. "This is never something we want to take place. Our store manager has made their best effort to make the situation right and will continue to work with the bakery team to understand what happened and ensure it doesn’t happen again.”

"It can’t make up for the embarrassment and humiliation she went through with family and school friends there," Nellie Flores wrote on Facebook.

Follow Joshua Bote on Twitter:@joshua_bote