We only have the tablets complaining about his copper because he literally saved them himself (multiple complaint tablets found in what is presumed be be his home.) (I imagine him going into his hate mail room periodically to reread old mail and just be like : "yes. Let the hate flow through you")

Also, saved clay tablets likely wouldn't have survived unless they'd been fired in a kiln. So why are all these tablets he saved still around? Two possibilities I can think of: - he wanted to keep them, so fired them himself, OR - he pissed people off enough that they burned his office down

Hate mail and his receipts for his clothing purchases. But yeah, hardly small-time. Guy was working a LOT of scams...