Motorists who use Gull's self-service station may have got less than they bargained for earlier this week after a mixup with the price signs.
One motorist, who declined to be named, visited Hamilton's Norton Rd station on Tuesday morning and filled his vehicle with $146 of petrol assuming it was charged at $2.05.9 per litre as shown on the sign, but his receipt showed it was charged at $2.12.9.
He complained to Gull, and is still working with the company to reach agreement.
Gull retail manager Graham Stirk said they had had only one complaint.
He said the mishap occurred because contractors "overlooked changing one side of the sign", and it was corrected the same day.