Local vendors denying to make stamp for our company

I have recently started a private limited company in Palakkad, Kerala. After registration was completed, we wanted company rubber stamps. We prepared a letter for stamp in the company letterhead and approached a rubber stamp maker at Palakkad. He asked to come after 2 hours and when asked, he said he cannot give the stamp as he does not know if the company is genuine. Then we approached another vendor and the same story repeated. We understood that the first vendor has informed all vendors in the area that ours may be a fake company. How do I make a legal complaint against these people?