Lost my parcel AGAIN!

So Courier Guy lost yet another one of my parcels. First they keep on ignoring my questions for a week. At 16.00 the day before everything closes for December holidays, I get a Whatsapp telling me "I regret to inform you I have searched all angles and cannot find your parcel". What? How do you loose a parcel with a tracking number? The only explanation is that Courier Guy did not do their job. A parcel cannot disappear. Someone at East London depot did not do their job. What am I to do now, as it was Christmas gifts which a client ordered from me. I cannot replace it, as it was specifically made. Plus, how can I replace it, it won't be in time for Christmas. If they actually answered me when I started to query , maybe I could still do something. But hey, why would Courier Guy need my R2000 (yes I send a lot of parcels for my shop) business per month, they certainly have lots of customers.