Budget mobile phone retailer Kogan Mobile says it has been "muscled out" of the industry by "telco heavyweights".
Telstra announced on Monday it will terminate Kogan customers' 3G network access some time in the next 30 days, essentially killing the company.
The move was prompted when ispONE, who supplied Kogan with 3G services purchased wholesale from Telstra, entered voluntary administration on Monday, severing their contracts.
Kogan and Telstra were not able to negotiate a direct supply agreement, unlike supermarket ALDI, who were likewise serviced by ispONE.
Kogan said it had made "numerous and concerted" efforts to convince Telstra to continue servicing its customers.
"We're devastated," the company wrote on its website.
It claimed to have been the victim of a power play by established telcos upset with Kogan stealing their customers.
"When over 100,000 people took their services to Kogan Mobile, in such a short space of time, it attracted a lot of attention.
"Frustratingly, it appears like the telco heavyweights may be determined to take their former customers back ... by force."
Telstra said existing Kogan customers would be moved to a temporary seven-day plan at some stage over the next month, after which their service will be cut off.
They will not be able to top up their credit but Kogan will offer pro-rata refunds to any customers with credit remaining when their service is terminated.
Customers will be able to transfer their phone number to another provider at any time over the next 180 days, Kogan said.
Optus has already pounced on the imminent exodus of customers, offering free additional data and call time to people who bring their number over.
