Suppose that on April $26,$ a customer takes a long position on ten June $23$ gold futures contracts at a futures price of $$2,020$ per ounce. One futures contract calls for the delivery of $100$ troy ounces $(1$ lb $=12$ troy ounces$).$

Let the initial and maintenance margin levels be $$8,300$ and $$6,150$ per contract, respectively.

Suppose the settlement price at the end of the first day is $$2,015$ per oz; on the second day, it is $$2,013$; and on the third day, the settlement price is $$2,010.$

When will the customer get a margin call? What amount will the call be for?