Amazon - Refund not received

I got my package which was noise shots X* Bass truly wireless earphones on **st of July **** as soon as I opened the package the charging case of the earphones was missing I registered return for that package on *nd of August a delivery boy came and took that package from me and he took the package and went away and cancelled my return request so he took my earphones and went away and from *nd of August **** I am trying to connect to Amazon customer care but they aren't responding me they are saying that they will solve the issue and will get the refund but they aren't doing that and I am tired of that customer service and I even tried to connect to them through email and Twitter but it was of no use they still haven't refunded my money nor given another piece of that item