Company declining payment of salary

Sir, I had been working for a company in Mumbai 5months ago. But I could only complete a tenure of 1month before I could leave for my further studies. I was not expecting to secure a seat in my college but it resulted in my favour and the joining date was within 10days. I informed the HR about this immediately and she asked me to wait before I tell anything about this to anyone in the management. I did as she said and finally I mailed officially about the resignation. I was still serving probation period and in the company policy, the notice period was not mentioned for them within the probation period. But still I served the company for a week extra apart from the 1 month tenure on the request of the HR. Before completion the exit formalities the HR told me that my salary will be credited within 45 days according to the company policy and I clarified this multiple times with her before performing the exit procedures. Now its been 5 months and there is no positive and clear response from the HR or from the company. The HR said that the company forced some new policy which doesn't allow payment to be credited to people who didnt serve the notice period, for which I said that since I left the company before this policy, it does not apply to me. The HR is giving this response after almost 5months of waiting. She claims that this clause of the companys right to ammend the policies without notice is applicable even to me. I am confused what to do and I feel cheated.