FALCON residents Julie Heeley and Lisa Kirby have not had mobile phone coverage in their area for eight weeks.
They are concerned there might be an emergency and Vodafone and Optus customers will not be able to call for help.
Ms Heeley said she had complained to Optus but to no avail.
Ms Kirby said the Optus website had been saying for weeks that there was a fault which was under investigation.
The women complained to Dawesville MLA Zak Kirkup, who was also experiencing issues with his Optus service at his electoral office.
While Mr Kirkup had switched to Telstra, the residents said they were already on plans and not in a position to switch providers.
Glenda Cooper, from Canning MHR Andrew Hastie’s office, said they had been liaising with Optus and the issue with the mobile phone tower was scheduled to be fixed, but maintenance was delayed due to inclement weather.
She said it was due to be fixed on August 16 or 17.
While the Falcon tower caters for Optus and Vodafone customers, the functionality of the site is managed by Vodafone.
A Vodafone spokeswoman said a third party had installed a large advertising sign at the site, blocking the mobile signal.
“We are trying to get the third party to remove the sign to restore coverage as soon as possible,” she said. “We apologise to customers for the inconvenience this is causing.”