The content of the tablets is entertaining. I didn't know there was more than one. https://www.forbes.com/sites/kristinakillgrove/2018/05/11/meet-the-worst-businessman-of-the-18th-century/

One from Arbituram:

Why have you not given me the copper? If you do not give it, I will recall your pledges. Good copper, give again and again. Send me a man.

And another from Arbituram:

Why have you not given the copper to Nigga-Nanna? Ili-idinnam says 'The copper that Nigga-Nanna has received is mine!' Be kind enough to give the copper, as much as he has a claim on you, to Nigga-Nanna.

Two other people start writing, asking that he give copper to Nigga-Nanna:

The copper of mine, give it to Nigga-Nanna - good copper, in order that my heart shall not be troubled.

May Samas [the sun god] bless your life. Give good copper under seal to Nigga-Nanna. Now you have had me issue 10 shekels of silver. In order that your heart shall not be troubled, give good copper to him. Do you not know how tired I am [of this]?

Another person, possibly a business partner, gives instructions to Ea-nāṣir:

With regard to the copper of Idin-Sin, Izija will come to you. Show him 15 ingots so that he may select 6 good ingots, and give him these. Act in such a way that Idin-Sin will not become angry.

And of course:

Now, when you had come, you spoke saying thus: 'I will give good ingots to Gimil-Sin'; this you said to me when you had come, but you have not done it. You have offered bad ingots to my messenger, saying 'If you will take it, take it; if you will not take it, go away.' Who am I that you are treating me in this manner -- treating me with such contempt? and that between gentlemen such as we are. I have written to you to receive my money, but you have neglected [to return] it. Repeatedly you have made them [messengers] return to me empty-handed through foreign country. Who is there amongst the Dilmun traders who has acted against me in this way? You have treated my messenger with contempt. And further with regard to the silver that you have taken with you from my house you make this discussion. And on your behalf I gave 18 talents of copper to the palace, and Sumi-abum also gave 18 talents of copper, apart from the fact that we issued the sealed document to the temple of Samas. With regard to that copper, as you have treated me, you have held back my money in a foreign territory, although you are obligated to hand it over to me intact. You will learn that here in Ur I will not accept from you copper that is not good. In my house, I will choose and take the ingots one by one. Because you have treated me with contempt, I shall exercise against you my right of selecting the copper.

Apparently Ea-nāṣir started having money problems later, and had to stop selling copper. I don't know if Forbes is just making things up, but that's what they said.