Non issuance of experience letter

Hi all, One of my friend worked in a textile company which is situated in Ludhiana punjab. He worked there for 1 year and 7 months, due to financial needs he had to resign the job and had to join with some other company at higher package. Points which speaks on his behalf - 1. He served the notice period of 1 month which was also approved by the immediate supervisor so no issue raised here by management. 2. HR team processed the Full and Final without any deduction as he follows the exit policy , which is obvious. 3. There was probation period of 1 year which he worked there and also got confirmed and have confirmation letter also. Even he worked 7 months more than probation period (1 year 7 months total work) But now his employer not providing the experience letter, its been 5 months and they denying to provide it by stating that 1. you have left the organisation at the peak time 2. You should complete one more year after your probation to get eligible for experience letter (which is mentioned no where in offer/appointment letter 3. Now challenging that go where ever you want, go legal , we don't fear of it, you can't sue us to provide the experience letter Please tell me what can be done in this case.