I am sorry you had a low review here are some tips to help you prevent such reviews.
Be Transparent: Transparency is something many sellers lack. Be extremely clear with the buyer and in your gig description
Set realistic deadline or delivery dates: If the timeframe is not enough for the job, just tell the buyer. If he refuses to place the order, you save your health and a bad review.
Update the buyer with job progress: If within the project, you realize you can't meet up with the delivery date, write the client a day or two before the actual date explaining why you can't meetup. They might get angry but most will understand.
Be real with your experience: Lying about your experience increases the buyers expectation. if you lack experience in the field, Take it off from your Gig description and profile. There are many ways to write attractive selling gig descriptions without including experience.
Set realistic expectations and define the scope of the work so the buyer knows exactly what they are getting even before starting the project. Doing so will safe you from a lot of headache and scope creep.