The National Consumer Commission (NCC) will spend the next 12 months unpacking claims that certain mobile network service providers were proposing unfair call and data tariff increases.

In April, following a public uproar over proposed cellular tariff hikes and the receipt of consumer complaints against the proposed changes, the commission initiated an inquiry into the claims.

The inquiry had now become a full-scale investigation into the network service providers and the relevant terms and conditions, as the actions seemingly went against the Consumer Protection Act, which determined that a supplier was required to notify the consumer in writing or any other recordable form of any material changes to a fixed-term contract.

It was also presumed unfair for a supplier to increase the initially agreed-upon price in a contract term without giving the consumer the right to terminate the agreement.

Consumers who felt the network service providers would be acting unfairly if they increased the tariffs of existing fixed-term contract holders had aimed thirty-one complaints at Vodacom and one against Cell C.

This emerged as cellular-related complaints ranked third-highest among the complaints received by the NCC in the 2014/15 financial year.

Of the 946 complaints, 25% related to contract cancellation, 24% to poor service delivery and 21% to defective handsets.

The NCC had informed the network providers of the impending investigation after obtaining more information from the Independent Communications Authority of South Africa, MTN, Neotel, Vodacom and Cell C.

The NCC aimed to conclude the investigation within a year.