Starbucks (SBUX) is facing a lawsuit over the treatment of some handicapped customers by employees.

The customers are part of a group called  Deaf Chat Coffee, which is an organization that helps set up social gatherings for the hearing impaired. The lawsuit was filed on behalf of 12 people, and claims that  the customers were abused by Starbucks employees on multiple occasions, reports USA Today.

Among these claims are those of Alan Roth, who alleges that a Starbucks employee laughed at him when he tried to order. Roth claims he asked the employee if she had a problem with him being deaf. The employee allegedly started screaming obscenities at Roth, other Starbucks employees told him to leave and not return, reports The Huffington Post.

“Discrimination of any kind at Starbucks in unacceptable,” Jamie Riley, a Starbucks spokeswoman, told USA Today. “We take these allegations very seriously and believe that they are neither in line with our values nor our track record of engaging the deaf community as partners and as customers.”