How to hold them responsible?

Cried out of frustration trying to get info on undelivered parcel. Spent 3 hours on the phone, waiting, being bumped around, being dropped, then calling again. Finally was helped by wonderful agent who held me on the line as her supervisor personally called the ops manager (who doesn't pick up otherwise). Turns out the "failed delivery" because of "wrong code" (there has never been a code) was not a delivery at all. Parcel "somewhere in warehouse". The agent promised to personally follow up. I'll wait and see.

In the past, I've stopped using online platforms that use Dawn Wing because they are imossible to contact, their delivery guys and supervisors lie, and (I most resent this) they once after a week of calls delivered a wet box of empty bottles of wine to me.

How to hold them responsible, though? All these reviews and companies keep using them.