Delhi University — Regarding admission process

I gave duet2021 for msters in history (pg) and got selected for du sol in 4th list for which I received the registration link and fill the same and submitted but after that I didn't got the fees link, so I waited for some days but I didn't got the link so I decided to get in touch with du sol admission wing but no helpline was responded back by them..so I approached the du sol window and complained about the issue but no action was taken instead I got an email from their side mentioning that I didn't shortlisted for any admission list than I approached the du sol Admission window again and they said that the classes has started and admission windows are closed now so we can't do anything. It is very unfair on the part of a student how they can be so irresponsible towards their duty I'm really sad that the justice is not served to me as my whole year got wasted. University of Delhi is one of the top prestigious universities of our country and such a behaviour is not expected from them, plz provide me with some solution as soon as possible 🙏