It's not an exception. For example, a lady can have her nails done, or she can have her hair done, which means she goes to a solon and pays for getting her nails/hair done.
But getting something done, cleaned, washed, etc. doesn't always have something to do with paying. Get + past participle means a new quality/condition of something (it's the same with adjectives, e.g. get cold/warm/expensive/tough etc). Past participles are like adjectives (which vase? - broken vase). So, if you get a vase broken, it doesn't mean you pay for it. It means you make this thing happen - you break a vase, or you get it broken.
Now, if you get a job done, you simply do the job.
BUT depending on the context, getting a job done can mean paying money for it. For example:
Can I get the job done by Friday? - Sure, it'll cost you 500$.
In the context of the sentence above it's clear that the people are talking about some service.
But your sentence is clearly about some job people have to do themselves.
So, to sum it up, to get/have something done doesn't always mean someone doing something for us. Sometimes it means our own efforts. How do we know which is meant? The answer is simple - context.