Organizers at Apple’s Towson Town Center store in Maryland claim that the company isn’t telling the whole truth when it comes to withholding benefits from workers at the location. As the company’s first retail location to unionize in the US pushes to negotiate a contract, workers say it’s making it difficult for them to bargain for their benefits.

In a letter addressed to Tim Cook, the negotiating committee says they’re disappointed to learn the company won’t be offering workers at the location some new health and education benefits that are rolling out to other retail employees. The union also says that Apple has been spreading “misinformation” by saying workers would have to bargain for those benefits to be included in their contract.

“There is crucial context missing in this communication around the process of change within a unionized store and the fact that we can, and we will include these (and any new benefits) in our collective bargaining contract proposal,” says the letter, which you can read in full below. However, the union also claims that Apple has made it difficult to bargain for those benefits by not sharing “any details” about them.

Apple didn’t respond to The Verge’s multiple requests for comment on the union’s accusations.

The union, known as IAM CORE (CORE stands for Coalition of Organized Retail Employees, and the organization is partnered with the International Association of Machinists and Aerospace Workers), won its union election by an almost two to one margin in June. Since then, workers at other locations say the company has continued to oppose unionization efforts, with the Communications Workers of America filing complaints about Apple’s behavior in New York and Oklahoma.

Notably, the reports about Apple withholding benefits came out days before the Oklahoma store was scheduled to hold its union election, which IAM CORE’s letter says was a “calculated” move. If it was, it didn’t work: workers at Penn Square store in Oklahoma City voted to unionize in a 56-32 vote.

Still, there are still ongoing union drives at Apple stores in New York and Atlanta, where the threat of withheld benefits could sway votes or even stall the process of holding an election entirely. The union involved with the campaign in Atlanta canceled the vote in May, saying Apple had made it impossible to hold a fair election.

Earlier this month, Bloomberg broke the news about Apple’s push to withhold benefits at Towson and provided some details about exactly what workers might be missing out on; the list included a free Coursera subscription, prepaid tuition at some colleges (versus the reimbursement model Apple usually uses), and new healthcare plan options. The publication cited Harvard Law School professor Benjamin Sachs, who said that there was nothing stopping the company from offering those benefits to unionized employees.

Wilma Liebman, a chairperson for the National Labor Relations Board, told Bloomberg that the company’s move to block benefits could be a violation of labor law, saying it was “hard to see how they could come up with a legitimate reason for the timing other than to influence the outcome of the election.” According to the NLRB’s site, employers also aren’t allowed to “refuse to furnish information the union requests that is relevant to the bargaining process.”

As for the workers in Maryland, they hope the letter will spark a conversation with leaders at the company and store. IAM’s president, Robert Martinez Jr., promised in a press release that he would “sit down with CEO Cook anytime” to support the union’s members at Towson.