Countdown customers are angry after being woken up by a text message the supermarket sent out in the middle of the night.

The message, promoting a fuel discount, had phones beeping away in the wee hours of Sunday morning. But Countdown may not be to blame, with the Spark mobile network experiencing issues overnight.

An Auckland woman and her family woke up with a fright when her phone went off at 1.19am.

"You don't expect something from Countdown in the middle of the night. You just panic," she told Newshub.

"I'm staying in a small room at the Notovel Hamilton, and it woke my entire family up.

"I was pretty angry. It took me a long time to get to sleep."

The woman, who would prefer to remain unnamed, said she doesn't even shop at Countdown, and says Pak'nSave will have a similar deal running "so it was a waste of bloody time telling me about it anyway".

She said she would like an apology.