The Dimitros Company records the following transactions during September 2018:

• Cash sales to customers totaling $6,800.
• Credit card sales to customers totaling $21,500. The credit card fee to the merchant is 3.0%. The credit card companies have paid all amounts due for September.
• A $3,000 sale on account to a long-time customer with terms of 2/10, n/30. The sale is made on September 5. The customer pays the invoice on September 14.
• A customer returns product they had purchased last month for $450. Dimitros accepts the return and gives the customer a cash refund.

Calculate the following amounts:

1. Service charge expense for credit card sales
2. Sales discount (contra-revenue) for sales on account
3. Sales returns (contra-revenue)
4. Gross sales revenue
5. Net sales revenue
6. Net cash collected from sales