Australia’s largest telecommunications company, Telstra, is investigating a phone service outage after angry customers employed Twitter to complain they were having issues Tuesday. A representative of the firm said it was fielding reports of problems making calls to and from fixed-line and mobile phones, according to the Sydney Morning Herald.

“We’ve received reports from some customers facing difficulties making voice calls on our networks,” Telstra itself tweeted. “We’re investigating as a priority.” The company also wrote: “We can confirm we have resolved the issue. We’re sorry for any inconvenience.”

Most of the affected customers appeared to be in Tasmania and  Victoria, “with some impact elsewhere,” Australia’s ABC News reported.

The interruption in service marked Telstra’s third mobile outage in two months. Last week, a national outage affected roughly 8 million accounts. Some customers were reconnected in 90 minutes, while others had to wait four hours. In response, the company has planned to compensate customers with a free data day April 3.

In February, an outage wreaked havoc on mobile and internet services across Australia. This one was reportedly blamed on “human error,” and also resulted in a free data day. 

The outages are an issue for Telstra because it has leaned on its perceived network superiority to justify its premium prices.