The Salvation Army is hosting a "Santa's grotto" for families and clients this year. A room at the army's office and church on Cameron Rd is already partly decorated for next week's event, which offers people a special Christmas if they are unlikely to have one themselves.
Morris said they were going to head out today to visit those people who would not be able to make it to next week's event "but now we'll be busy trying to find two new wheels".
"We are going to have to replace the tyres and everything else. That's money that's not going to the needy. It's going to affect what we can do."
In recent weeks, the Salvation Army has also had to spend $500 to $600 on replacing wing mirrors on the vehicle after they were smashed off.
"It's when you see the best and the worst of people - this time of year," he said. "It hurts. It makes it difficult to do the job."
Morris said Christmas was an important and busy time of the year for the Salvation Army, which regularly distributed food and support to those going without in the community.
Some of the food the Salvation Army offers at this time of year comes from a can drive run by emergency services this month.
A police media spokeswoman confirmed they received a report of the theft but "there are no lines of inquiry to enable us to establish who was responsible".
The spokeswoman would not comment further.