私が送った商品が貴店に届いたと思いますが、商品の状態を確認してくれましたか?貴店から新しい商品をいつごろ発送できるか教えてください。
また、追跡番号と大体の到着予定日を連絡ください。
I'm assuming that you received the merchandise I have returned to you. Did you have a chance to take a look at the conditions of the merchandise?
Could you please tell me when you are going to ship the replacement?
I would really appreciate it if you can give me the tracking number and the estimated date of arrival for the replacement. Looking forward to hearing from you.