Error- Index (zero based) must be greater than or equal to zero and less than the size of the argument list

I am using string.format properly but still getting an error mentioned below:
Error: Index (zero based) must be greater than or equal to zero and less than the size of the argument list
Code where i am getting an error: string.Format("{0},{1},{2}", "\"" + brand + ", " + productName + ", " + CurrentProductFamily.ClassName + "\"");

Any idea?

Thanks in Advance.