I don't have a relieving letter from my two previous companies. I worked for 4 and 9 months in the first and second companies, respectively. I'm unable to reach out to one of the companies but have contacted the second one. They mentioned that they cannot provide the letter as I resigned without serving the required notice period of 3 months. What should I do now? Will this situation affect my chances of securing a job in a reputable company in the future?