My employer does not give me a letter/ email stating that I did not sign a non-compete with him.

I haven't signed a non-compete with my employer when I joined the firm. The only thing that was given to me was an employment letter. I want him to give me a letter or at least an email confirmation stating that I do not have any agreements ( especially non-compete) with the firm. But he or anyone from the firm refuses to give me the letter/ e-mail. I have been trying to follow up for almost a month now and for 2 weeks they have started to ignore my calls and messages as well. I want to apply for a full-time position in another firm and the same firm asks me to get this letter/ e-mail from my current employer to avoid legal issues in the future. I see no reason why my employer is doing this except for that I will be not working on his payroll anymore. He simply asked me to leave the company whenever I want to, but he would never provide such an email or anything. I will not be able to get my other job unless I have this confirmation. I am really stressed and don't know how to proceed. Please advice.