Appropriate Action

I was a student of llb 3 years course at Delhi University Campus Law Centre. In my 5th semester I had got 46 marks for which I applied for improvement exam. On the day of exam I fell ill and couldn't appear for the said exam. The rule as mentioned on du website, du ordinance and on the improvement form is that the previous secured marks shall be carried forward if a student remains absent in the concerned exam. Now the officials at du say that the rule of carry forwarding marks does apply to llb since it is a professional course but this rule is no where mentioned on their website and on all the documents which are accessible by the students. The official at the du told me on my face that such rule of not carrying forward marks in llb is nowhere written but it's a rule. I know that a rule becomes applicable only if it is in public notice and is accessible by all. I have approached everyone from lower level to higher level wrote so many applications but they aren't ready to listen not even giving me written reply as to why my application is not accepted. Plus they are not showing me the rule where it is written that marks will not be carried forward for llb course. Because of all this my one year is getting wasted. Please tell me what's the appropriate action that I can take against the du.