Some Wanganui locals thought they had paid the money to buy the equipment for the digital switchover.
However, a disgruntled caller said he and others he knew have had to pay $25 to have their decoders retuned.
What they did not know is that on October 9, Sky changed its free-to-air Freeview Satellite Service and it was now being broadcast directly by Sky TV.
The Sky TV version of Prime is still broadcast free-to-air, unencrypted, and is accessible by most Freeview satellite receivers.
Freeview general manager Sam Irvine said most Freeview-approved receivers (those that carried the Freeview logo) should have automatically updated to the new Prime service.