Tesla buyers in Germany may find themselves €4,650 ($5,410) out of pocket soon, after the government decided that they must immediately pay back the incentive they got when they bought a Tesla Model S.

The Federal Office for Economics and Export Control (BAFA) said that people who bought a Model S before March 6, 2018 are not eligible for the “environmental bonus,” and it must be returned. Altogether just over 1,000 buyers will either not get the bonus, or have to give it back.

“Over the past few months BAFA has tried to reach an amicable solution in the interests of the customer in talks with Tesla,” the press release said. “Unfortunately, that did not work. Due to the requirements of administrative law and budget law, BAFA is now forced to carry out the reversal process.”

Tesla said it would cover the cost of the incentive loss for Model S buyers while it appeals the decision.

The back-and-forth between Tesla and the German government over whether or not the Model S should qualify for the incentive has been going on since 2016.

The rule is that only electric cars up to a cost of €60,000 are eligible for the incentive. The program was devised between the government and the German car industry, which is contributing financially, leading Tesla to argue that the price cap deliberately excluded its cars from the scheme. The government maintained was that it was not possible to buy a Model S for that price, so Tesla got to work stripping extra features out of the car to get the cost down. It won back its buyer incentive in March this year.

Tesla drivers who bought the Model S since March can keep their bonus, since Tesla proved to the government that it can sell a basic car for €60,000.