Is it possible to rank first on Google through deception or money?

[Cupernicus]

Hello; Our website is currently ranking 4th on Google for a particular keyword. One of our competitors is usually at the end of the first page or on the second page. However, this company announced a 20% discount on a product related to that keyword in February on its website. Between February 1st and 28th, it consistently ranked first on Google. As soon as March 1st hit, it dropped from the first page, and was not even on the first three pages. Today, it has regained the first position again. When I mentioned this to a friend, who is the owner of an advertising agency, he mentioned that someone told him Google sells the first position for a high amount of money. I have never heard of this before. When I researched in Turkish and English, I read statements from Google denying this claim. Do you have any information regarding this? Does Google sell the first position for money, or does a company reach the first position through dishonest means? Because the competitor is a big company, and I don't think they would easily resort to dishonest tactics.