The US government hasn't given up its attempts to stop the AT&T-Time Warner merger.

On Thursday, the Department of Justice filed an appeal to last month's court ruling, which cleared the way for AT&T's acquisition of Time Warner.

AT&T told PCMag it was "surprised" by the move. A mere days after the court ruling, the carrier completed its purchase of Time Warner for an estimated $85 billion.

"The Court's decision could hardly have been more thorough, fact-based, and well-reasoned," said AT&T general counsel David McAtee, who said the carrier plans to fight the appeal in court.

"While the losing party in litigation always has the right to appeal if it wishes, we are surprised that the DOJ has chosen to do so under these circumstances," he added in a statement.

Last November, the Justice Department sued to block the takeover on antitrust grounds, prompting the legal battle. "We continue to believe that the pay-TV market will be less competitive and less innovative as a result of the proposed merger between AT&T and Time Warner," US assistant attorney general Makan Delrahim said last month. That same statement hinted the US government might appeal the ruling.

President Trump has also said he opposes the merger; he claims it would concentrate too much power into the hands of one company. "I think your pricing is going to go up," he told reporters last November.

Indeed, after AT&T completed the acquisition, at least one of the company's fees has gone up slightly. However, the carrier also plans on pumping more money into its new properties, including HBO, which it now owns via Time Warner. To attract more HBO subscribers, AT&T has said it's going to boost the network's original programming budget.