Immediate resignation due to health issues, not serving the notice period and experience letter.

Hello! I worked as a full time employee (Chef) at a Cafe/Patisserie for some months (less than half a year) and due to health issues, I decided to resign immediately without serving the notice period and sent across a letter (email) to my employer regarding the same. My job requires me to work physically and I didn't see myself in the position to complete my notice period. Now, upon asking my employer to help me with the experience letter and settle my final payment, he tells me I am not entitled to an experience letter since I did not complete the exit procedures properly and I am supposed to pay one month's salary to the company only then the final settlement can happen and he'd give me the experience letter. My question is, is this valid? My offer letter only said about probation period, salary, joining date, my position and notice period in case i leave and was a brief one. It does not mention anywhere that if I fail to complete my notice period, i won't be given my due salary (for the days worked) or won't be issued an offer letter. I also wanted to know if such laws actually exist/work for a small company (a cafe in my case) and what I must do now. Thank you!