Advice for dealing with vendors

[OrcishOrchids]

Hi everyone, I'm at a bit of a loss really and need some tips. I recently had to switch from buying locally to ordering online (my local place stopped selling orchids) and I've been having a difficult time with vendors not shipping things in a timely manner. Sometimes it's the vendors fault, sometimes it's the shipper, but either way my plants are dead on arrival. I try to be polite and helpful, but it isn't like I can show up and make a fuss so it seems like I'm not much of a priority.

So what is your favorite way of dealing with unresponsive or unhelpful sellers?