Sorry to hear you are having issues. Fwiw, we received a regular letter this week. Maybe it's worth asking at the Dulwich delivery office (it's in West Dulwich, though. Their phone number is 03457740740) to see if there are aware of any issues in your particular area? I've seen cases in the past were the a particular postie was sick and they didn't cover for them, they just let everything accumulate for a couple of days until the person was back.