I have a Panasonic Cordless

Question

I have a Panasonic Cordless tel phone mod.KX-TG607 5.8ghz expandable digital answering system.the ACD adapter for the base the wire shorted out.It was brought back to the store(Radio Shack) to replace the adapter.They replaced with their own brand.Now the phone has static and very low volume. The phone operated good before the adapter was damaged.Could this adapter sold to us be the problem?(radio shack input100-250vac 50/60Hz 0.5a output 9VDC 1.5A)