Glenolden, PA (KYW/CNN) - A Catholic high school student in Pennsylvania has been banned from attending the prom because she doesn't have a date.

Amanda Dougherty was gearing up to go the junior prom. She had already shelled out nearly a thousand dollars on a dress, shoes and tickets.

But when her date suddenly backed out, she was told by the school that she couldn't go alone.

A rule by the Archdiocese of Philadelphia bans students from attending the dance without a date.

"For them to say that we're not good enough to go unless we have a guy standing next to us. It's just kind of sickening," said Amanda.

"Amanda has been waiting for this for two years. To not be able to go, I feel horrible," said her father, Jack Dougherty.

The school released a statement saying, in part: "Our high schools offer numerous dances and events throughout the year where dates are not required, but we view the prom as a special social event where a date is required to attend."

Dougherty says she will fight to get the policy changed.

The big dance is Friday.

KYW/CNN