Settlement of additional costs for earthworks

Hello everyone,
we are currently building a single-family house with a general contractor and have now registered here to possibly gather your opinions here and there.
Right at the beginning of the house construction, we did not fully agree with our GC on the final billing for earthworks.
Previously, we were informed by a letter that the additional costs for earthworks were estimated and that the exact billing would take place after the completion of the measurement. We agreed to the aforementioned extra cost. The site manager referred to the soil report for the earthworks and calculated the amount of topsoil removal and filling with limestone from this.
However, the actual quantities of topsoil removal and filling were different because the executing civil engineering company did not consider the depth of topsoil removal to be necessary. At the same time, I must also mention that, at our request, more land was excavated than previously discussed with the site manager.
In the final billing, we were now informed that no additional costs would be incurred by us and that the previously calculated cost indications would remain. I have therefore asked the GC to explicitly provide us with a billing statement from the civil engineering company. The GC is not passing this billing on to us, stating: A healthy dose of mistrust is good, but no trust at all...!. Instead, we have only received a cost statement from the GC, which is no longer transparent to us.

What is your opinion on this? Is the GC allowed to withhold the final billing with the civil engineer from us? After all, this concerns additional costs of about €7,000, which, unfortunately, have already been paid by us!!!
Thank you in advance for your opinions, answers, and efforts!!

Best regards to all homeowners!

I don't understand? You commissioned the general contractor to carry out the additional work at a fixed price, based on your measurement. Now you had more excavated, get it at the same price, and want to see an invoice between the general contractor and the earthworks contractor that doesn't concern you? Be glad you don't have to pay any extra.

So, you had more area excavated than necessary for the house? These are do-it-yourself services that you arrange directly with the excavation company, meaning you should receive a separate invoice from the excavation company for the additional square meters. The general contractor has nothing to do with this, right?! In my opinion, there is no "offsetting" because everything related to the property is your responsibility.

Hello Wastl, the site manager first calculated the measurement with 0.55 cm of topsoil excavation – however, only 0.35 - 0.40 cm excavation was done. On the other hand, at our request, an area 1 meter wider for the future terrace and additional space for another parking spot was excavated than previously agreed upon. I recalculated using the rule of three and come to about €1000 less cost for the earthworks, which is probably worth following up on. Thanks in advance for your response. Have a nice holiday!

Why should the GU give you the invoice from the TB? That is between the two of them. The GU then writes an invoice to you. After all, you also have the contract with him. Or do you have the contract with the TB?

everything went correctly...there is nothing left to renegotiate...be glad that it stayed at the 7TSD.