Worlds oldest known written complaint is 3800 years old, about demanding reissue for sub-standard copper! Written in Akkadian cuneiform, around 1750 BC, the tablet was sent to Ea-nÄá¹£ir by a customer named Nanni. The tablet was discovered by Sir Leonard Woolley, currently preserved at British Museum
What about it?
https://en.m.wikipedia.org/wiki/Complaint_tablet_to_Ea-n%C4%81%E1%B9%A3ir
https://www.thearchaeologist.org/blog/complaint-tablet-to-ea-nasir-the-oldest-recorded-customer-complaint