Last time I had a parcel lost at Southampton by DHL it took DHL 2 weeks to declare it lost. I kept watching the tracking site on-line, and they were found, then: on the van for delivery, delivered -recepriant out (Bull-shit as I work from home, and was in all of the day they stated, and was watching the tracking, so knew it was on the van and was waiting for the delivery.), returned to base, on the van, returned to base, on the van, returned to base, dissapeared for a few days.... lost.
Southampton is one of their bigger sorting offices. So I am afraid that I don't hold out too much hope for you.
Have you asked Jam for the tracking code at DHL, you might be able to track it yourself on-line.?