Terrible service - Incorrect Parcel

I received the incorrect parcel from The Courier Guy, I called in as soon as I realised and was told to call again later because the only person that could help me was Trevor between 13:45 and 14:00. Trevor was extremely rude, condescending and unhelpful. I am sitting with someone else’s package and have no idea where my parcel is. The only feedback I got was they have to investigate whose fault it is before they can do anything. When I asked how long this will take I got told he is waiting for people to get back to him and has no idea. Very disappointed in this service and the way that this issue has been conducted