I think you run into a Microsoft Excel problem. In some versions of MS Excel saving an csv file exchanges comma with semicolon which makes the whole file not usable in InDesign.
You have to ask your client that he should send you either the Excel file, when you have an US version you can save it correctly as CSV or ask him to send a tabulator separated file which you could also use in InDesign.
Micrsoft is very bad when it comes to export in common file types in all of their programs.