Professional Courier - Package not delivered

I have booked courier from Banashakari *st Stage to HSR Layout on **/**/****, till now it is not delivered. I have received call from my client stating that same has not delivered in time, then I have tracked the status of the same in the professional courier website it showed its in hsr layout office, than I have send my client to collect the documents in hsr Layout office than they told it is not in this office. Then I have sent my office person to banashakari *st Stage office. In banashakari *st stage office they have not responded properly about the same, then I personally went to the office then also I did not get the response for the same but they told that I am talking nonsense. Then I also had coordinate with banashakari *st stage office Manager then he also stopped responding. Afterwards, I have raised a complaint on the website of Professional courier but the same is not use. Due to this I have lost my client and lost my fee. Please help me in this regard