You cannot go to a company where you received a job offer. Write a letter to the HR supervisor. In your letter: - explain why you are declining the offer - express your gratitude - explain why you like your current job very much

Dear Sir or Madam, I am writing to inform you that I have recently been offered the Landscape Designer position in your company and I am very grateful for the opportunity. But I regret to say that I cannot accept the offer right now.