Inconsistent, long delivery times.

Irregular delivery times. I sent a parcel from Dbn to Pmb. It arrived the next day. Makes sense. The cities are next to each other. Now a parcel has been sent to me in Dbn from Pmb and 4 days later has still not arrived. I'll use an overnight courier next time as they also charge R100. I'm disappointed in this service and just hope they haven't lost the parcel.