Panasonic — Air conditioner colling and compression vibration noise

Address:

G-1, 402, Opera Plam ,Pasodara Chokadi

I have AC buy just two day ago. Now AC colling like nothing, for example AC colling temp. 16' and 24' have zero temperature difference. Local service center said coling is working but any difference between 24 and 16, yes or no.
2 day ago installation time compression vibration problem start and engineers is fixed but now is starting again.
I told engineers, local service centers but is not answering properly. He said everything is good not problem in air conditioner.