Could you please assist with dealing with a certain job we have posted. We have hired a freelancer to undertake a task but they have not delivered the task we have specified. For example, they have advised they can obtain total number of sales of a product but can only provide % of sales which we have specified that we already had. What is the best way we can handle this given that we have not received what we asked for?
Politely thank the freelancer for their time, close the job and leave an appropriate feedback for this person. This should take you less than a minute, don't waste another minute on this person.
Then, hire someone else to do the job.
There is no "dispute."
You are a businessperson. Presumably you will hire many different freelancers to help you with your sales efforts. You will continue to work with the freelancers whose work you value the most. You will quickly stop working with freelancers who are not productive for you.