Any suggestions on how to get the mail

I was working in a startup as a web developer and i have two years experience in the same company. The startup decided to pivot to game development and asked us to learn or else leave . As we were already working on a b2b saas product and it got over . So the CEO decided to pivot as the investors are showing interest in Game development. I had a talk about my interest in continuing web development and he said you can leave after a one month notice period. So I said sure, as a startup there was no PF or any HR in the company. The CEO asked me to prepare the payslip and experience letter, he said he will sign and give it. I did the same and i got it. He said he won’t pay for the Xerox of the same as i decided to quit . I was like how low a person can go if they get to know they don’t need you . I had a huge respect for him , now I feel like maybe that’s what “corporate culture” is what everyone says. Anyways i messaged him to send me the experience letter and payslip by official mail , i reminded him 4 times in the past month. I asked one of my colleagues to remind him, the colleague said CEO said to ignore and block the number. but there is still no official mail. What’s the best way to politely ask him to send by official mail?