A Fiji businessman is furious after his Xtra email account was hacked and Spark's lacklustre approach to resolving the issue.
To make matters worse, hackers attempted to lure payees to transfer money into a fake bank account, claiming original payments had not been completed.
Vinay Kumar told the Herald he first noticed the issue on Tuesday and spent more than 48 hours trying to convince Spark of the severity of his situation.
"[The hackers] are sending emails of fake bank accounts to my suppliers to give money to them. I intercept 20,000 payments a day, luckily I stopped it.
"Since Tuesday I've been ringing to the Philippines, they don't really care there, they just say change your password," he said.
Kumar attempted to go to his local Spark store and address the matter with them but the store was closed and he had to call the helpline.
He said the people in the Philippines weren't able to offer any reasonable help and he needed to speak to someone from New Zealand right away.
"I don't know what they're doing. I have been on the phone with them [Thursday] , yesterday and Tuesday.
"Three of my suppliers were asked to send money to a fake account in the US and I got really scared they would make payment to a fake account," Kumar said.
A Spark spokesperson from New Zealand managed to get in touch with Kumar yesterday and told him he hadn't seen anything like it before.
Kumar was told Spark would inquire about the situation and get back to him.
In a statement, a Spark spokesperson told the Herald they were looking into "why the issue wasn't appropriately escalated earlier".
The spokesperson said Kumar complained to them about his social media account being hacked prior to his Xtra email, pointing to a possible connection between the two incidents.
However, Kumar said Spark's response wasn't good enough and people he's in business with could have lost thousands.
"Email is a main source of communication, it's used everywhere. These people aren't taking it seriously and from a business perspective what do you do.
"This has been my email for the past 20 years, this is why I don't change it," he said.
Spark has also undertaken a review to see if any other accounts had similar unusual activity, identifying "a small number of accounts" which had been targeted by a similar profile of a hacker.
"So we are taking steps today to secure these accounts.
"We are not aware that either Mr Kumar or any of these Xtra customers have experienced any financial loss as a result," the spokesperson said.