Hi SeattleGameboy,
Thanks for posting. Apologies that the information regarding your accessory warranty was not clear.
Parts and Accessories from Dell have at least a 90 day warranty, as explained here. While your post does not mention the part number of the product you purchased, this example has a 3 year warranty. However, normal wear and tear is not covered by warranty. From your post, the damage you mentioned would be considered normal wear and tear, as explained by this Dell knowledge base article.
Hopefully this information helps to explain things more clearly for you.
If you need additional assistance, please contact me privately. Be sure to include your personal information (name, address, telephone, email) and your computer's service tag number in your message. Thanks.