O2 has apologised for the outage last week, which saw its mobile customers stranded without any network service for the best part of 24 hours, and is now offering compensation for those affected.

Pay Monthly customers will receive 10% off their July subscription which will be applied on their September bill, which is equivalent to 3 days, while Pay & Go customers will receive 10% extra on their first top-up in September.

In addition, all O2 customers will received a £10 O2 voucher to spend in store, redeemable as part of its O2 Priority Moments app. This too will be available in September.

The country’s second largest mobile phone network went down at 1pm on Wednesday July 11, and for most of the day received little to no contact from the company, many users taking to Twitter in outrage. After engineers worked through the night, 2G services were restored at 8am on the Thursday, while 3G and data services did not return until 2pm.

"On Wednesday of last week we experienced a fault with one of our network systems which meant that one third of our customers devices could not register correctly on our network at some point over a one-day period. As a result, those customers could have experienced difficulty when making and receiving calls, sending texts and using data."

Needless to say, critics were not impressed.

"We hope that our concerns are unfounded and the Games pass without telecoms incident. Connectivity at the Olympic Park can at least be predicted and planned based on a greenfield implementation of the latest technologies and architectures. However, the UK as a whole must rely on previous investments to carry it through – and these have been less than optimal in the mobile space," said Ovum’s Steve Hartley.

The company told CBR the outage had nothing to do with Olympic upgrade works, or work on its network sharing agreement with Vodafone.

"The issue we had was unprecedented and we recognise that this caused inconvenience and frustration for those who had a disruption in service. We have now identified all those customers directly affected (those whose devices could not connect on our system) and are giving them the equivalent of three days back for the disruption as a gesture of goodwill and to say sorry," said a spokesperson.

O2 customers will also receive a text from the company before Friday 27th July to say sorry and with a personal confirmation of what compensation they are entitled to. Business customers with over 10 connections will receive communications through their account managers or O2s channel partners.

While rival operators have been looking at poaching dissatisfied O2 customers, UK consumers are usually reluctant to change providers, said Francesco Radicant from Informa.

"In the long term the outage will have a less of an impact as consumers will always have a financial and psychological resistance to changing their current provider. Furthermore, there is a lack of options and alternatives in the UK’s mobile market as consumers do not see a significant difference in terms of service quality between the operators."