Eskom is planning to disconnect supply to West Rand Power Distributors, saying that the company owed it more than R18 million.
The cash-strapped power utility said that it had notified the company of its intention to cut supply last month but received no response.
A deadline for submissions from all parties affecte had been set for Friday.
Eskom said that a failure to meet this deadline could lead to cutting off electricity until at least 4 February.
The decision could plunge thousands of residents living in the region into darkness.
West Rand Power Distributors were not available for comment.