Just make sure that the mouse was not the mother and that there is a not a small litter of them inside the sideboard. Can be surprising how devious they are in building nests in furniture/boxes.
You are entitled to ask the company to pick up the sideboard and to replace it with one that is clean. The mice may have urinated on the sideboard and you should not be expected to have to clean it.
If you have problems with the company, threaten to report them to the Trading Standards and Environmental health officials at the local authority nearest to where this company is operating from. Who knows this company might have thousands of Indian Mice in their warehouse.