You cannot go to a company where you got an offer. Write a letter to the HR supervisor to
1. Explain the reason why you decline the offer
2. Express your gratitude
3. Explain you like your current job very much.
Sample Answer of You Cannot Go to a Company Where You Got an Offer
I am writing this letter to inform you that I would not be able to accept the offers that given by your firm Colgate as I have decided to stay with the same company as of now. As I have been in the corporate sector for many years and it would be really great to work under reputed companies like yours.
I know how healthy the reputation of Colgate company globally and its dominance in the market. My career would be over the mountain if I had worked here for many days. I would really like to appreciate your offer, meanwhile, I would suggest newcomers join this company if they are given a chance in the future. I really love my present firm as they taught me a lot during my grey days in the market, moreover, I was also getting during sparked of Corona period, which was not expected by me though they helped me during tough phase as well. So it seems like I got a dream job for now, and I should not ditch them.
Hope your company would not mind my intention!