I need help with the journal entries for March 11 and 20

Journalize entries for the following related transactions of South Coast Heating & Air Company. Refer to the Chart of Accounts for exact wording of account titles. Mar. 1 Purchased $48,000 of merchandise from Atlas Co. on account, terms 1/10, n/30. period. Discovered that $7,500 of the merchandise purchases on Mar. 1 was defective and returned items, receiving credit. Purchased $6,000 of merchandise from Atlas Co. on account, terms Received a refund from Atlas Co. f 11 18 n/30. Received a refund from Atlas Co. for return on Mar. 11 less the purchase on Mar. 18. 20