Dozens of people have said they’ve received the messages, which began arriving more than a month ago.
Locals called on Vodafone for an explanation.
Vodafone marketing manager Lahaina Kiely warned users to not reply to the messages.
“These texts are from overseas and are spam,” she said. “It appears to only be targeting iPhone users.”
“As with any spam, the recommendations are, do not reply to the text message, block the sender and delete the messages.”
It’s not clear what the actual object of the messages is, if they are spam. Usually SMS phishing – known as smishing – attempts to trick recipients into clicking on a link, which may insert malware in the phone, or into replying to the message.
To filter and block messages on iPhone, go to Settings>Messages and turn on “Filter Unknown Senders”.
If a message is spam, tap “Report Junk”, below the message, to delete and send the message to Apple.
And to block the messages, tap the name or number at the top of the conversation, then tap the “More Info” button at the top right. Tap the name or phone number to view the contact card, scroll down, then tap Block this Caller.