Supreme Court of India rejected on Friday a plea by mobile carriers seeking corrections of what they called errors in the government’s calculation of their dues.

Last year, the Supreme Court gave telecoms companies 10 years until 2031 to clear dues owed to the government for use of the airwaves and as license fees, after they missed a January deadline to pay roughly $13 billion.

Friday’s ruling is a setback to Bharti Airtel and Vodafone Idea, which had approached the Supreme Court again this year, urging a re-calculation, but will have greater impact on heavily-indebted Vodafone Idea.

After the ruling, shares of Vodafone Idea fell as much as 14.6 percent to their lowest since October, while Bharti lost as much as 2.6 percent before reversing course.

Friday’s decision does not bode well for the recovery in the sector, ratings agency ICRA said in a note, adding that elevated debt levels and very low tariffs were likely to lengthen the process.

“The Supreme court has quashed the AGR penalty re-computation request of the telcos, stating that the earlier order states that no-assessment can be done. This will not bode well for the recovery in the sector and is likely to protract the same, given the elevated debt levels and very low tariffs,” Sabyasachi Majumdar, Senior Vice President & Group Head, ICRA, said.

India’s telecom industry is staring at high commitments towards debt repayments and DoT payments in the coming few quarters, with next major payments due in March-April 2022.

Vodafone Idea’s net debt, at 1.8 trillion rupees was high, standing at 10 times its operating profit for the year to March 31, calculations by brokerage Yes Securities show.

Vodafone Idea is losing subscribers at a time of talks with potential investors to raise funds in a market disrupted by Reliance Industries’ Jio telecoms venture launched in late 2016.

Vodafone Idea has paid the government 78.54 billion rupees in telecoms dues, regulatory filings show, but still owes roughly 500 billion.

Bharti Airtel has said it paid dues estimated at 180 billion rupees, but government figures show it owes a further 259.76 billion.

Jio, controlled by India’s richest man, Mukesh Ambani, has already paid off its smaller quantum of charges.