With all courier services it's luck of the draw. My last 5 consignments via DPD have all been returned to the depot flagged as "no access". I happen to live in a Tower block which involves the driver exiting his vehicle and walking 100 yards and getting in a lift to the 9th floor. Poor things it must be all a little overwhelming for them so they just take it back to the depot for the next mug to take out.
My advice is If your lucky enough to get the same driver every time, treat him like your long lost brother. Unfortunately I seem to get a different driver on each delivery, and I know that my local depot are up to all kind of shenanigans. I've now stopped complaining and resigned myself to the fact that next day delivery will actually take a couple of days to arrive after half a dozen phone calls to DPD customer services.
Today was typical 8AM DPD tracker shows out for delivery, by 12 noon it shows at the depot, 4 phone calls later and DPD have had to arrange a special courier pickup from there own depot, how ironic is that!