On September $1,$ the beginning of its fiscal year, Campus Office Supply Ltd$.$ had an inventory of $122$ calculators at a cost of $$20$ each. The company uses a perpetual inventory system. During September, the following transactions occurred:

Sept. $2$ Purchased $915$ calculators for $$20$ each from Digital Corp. on account, terms n$/30.$

$10$ Returned $29$ calculators to Digital for $$580$ credit because they did not meet specifications.

$11$ Sold $420$ calculators for $$30$ each to Campus Book Store, terms n$/30.$ Management estimates returns of $4\%$ based on prior experience.

$14$ Granted credit of $$870$ to Campus Book Store for the return of $29$ calculators that were not ordered. The calculators were restored to inventory.

$29$ Paid Digital the amount owing.

$30$ Received payment in full from the Campus Book Store.