Sql query to find the customer having due amount

Question

It was a billing application and I got stuck to get the output

 

Requirement:

I want to get which customerID has due amount on which InvoiceNo by what amount

 

 

as CustomerID 1 having total Bill Amount 1000 and had paid 1000 (200+100+700) as AdvanceAmount, that means Invoice 1 is totally paid, and hence customerID 1 is having a due amount of 10000.

 

I cannot able to write the query for the above problem.

 

Output should be the row having InvoiceNo2 with due amount 10000.

 

Here's Table structure

CREATE TABLE [dbo].[AdvancePayment](
    [ID] [bigint] IDENTITY(1,1) NOT NULL,
    [Date] [date] NULL,
    [CustomerID] [nvarchar](max) NULL,
    [InvoiceNo] [nvarchar](max) NULL,
    [BillAmt] [decimal](18, 2) NULL,
    [AdvanceAmount] [decimal](18, 2) NULL,
    [Status] [nvarchar](50) NULL,
    [CreatedBy] [nvarchar](max) NULL,
 CONSTRAINT [PK_AdvancePayment] PRIMARY KEY CLUSTERED
(
    [ID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]

GO