"By contacting customer service you get absolutely nowhere - they are in the Philippines and don't even know what deals are going on," Ms Denton said.
"It's unbelievable, and they call themselves a communications company."
Still without a phone, Ms Denton said she was then told one would be "installed" by January 19. A wireless home phone plugs into the wall but operates on a mobile network, so does not need any infrastructure installed.
Despite this, Ms Denton said contractors arrived to install a phone line, saying a connection would happen in the next few hours - but still nothing.
"They've then succeeded in cutting off [the neighbour's] phone and internet."
The 83-year-old said luckily she was able to use Skype to keep in touch with her two daughters overseas, but said she had friends in Auckland and elsewhere in New Zealand who she missed catching up with.
Rest home manager Chris Mcfarlane said two other residents were having similar problems and she had spent hours on the phone trying to sort it out on their behalf.
"I rang them as a person who recommends Vodafone [to residents]," Ms Mcfarlane said. "It's like banging your head against a brick wall."
A Vodafone spokeswoman said there were some errors made by the customer care team when they initially processed Ms Denton's request for a home phone wireless connection.
"Our team have since contacted Enid and apologised profusely for the inconvenience this caused. We are now on track to ensure Enid's home phone wireless connection is up and running ASAP this week."