If one of your best-selling gigs has been removed from search and promoted gigs, follow these tips: 1) Review Fiverr's guidelines. 2) Contact Fiverr Support for clarification. 3) Revise your gig's title, description, and pricing. 4) Optimize gig SEO with relevant keywords. 5) Improve gig images and description. 6) Encourage positive reviews. 7) Promote your gig externally. Be patient and persistent in your efforts.