A lack of spectrum, market saturation, "exploding" data traffic and declining voice call revenues are some of the reasons why South Africans are not paying less for data, according to the country's major network operators.

Electricity prices and load shedding have also led to a 33% increase in power and fuel according to at least one major network.

Mobile networks are now working hard to find ways to reduce the cost of data, saying making available more spectrum would play a significant role in reducing cost.

This is according to submissions made by networks Vodacom, MTN, Cell C, Neotel and Telkom to the public hearings on the cost to communicate yesterday.

They made their cases on why cost is priced the way it is, a day after organisations and the public made submissions calling for a decrease in costs and more regulation.

"It's evident that the spectrum availability plays a significant role in cost to communicate. What we can say is it would have a significant impact. If we don't get access to additional spectrum we need to densify," said Hennie Jacobs of Vodacom.

Spectrum refers to all wireless signals, which includes TV, radio, GPS and mobile broadband. Jacobs said the reason data costs were so high was due to the "spectrum crunch" in large urban areas.

MTN's Graham de Vries said the company has undertaken several measures to reduce costs it can control.