received email saying "The order was for an iPhone that shipped to New Orleans LA in October and has logged into your iTunes account." my id was blocked please help

I bought an iphone 6s last month and shipped it to my house. When I started using it, I logged in on my itunes ID. Later, I received the following email. I don't know what happened because I didn't dispute any order and I have no idea how to unblock my ID. Please Help.

Your dispute for $816.41 on order W449978253 has been assigned case
number 306165800. The order was for an iPhone that shipped to
New Orleans LA in October and has logged into your iTunes account.

We require additional information regarding the reason for the dispute.

When Apple receives a dispute, our established process is to take action
that protects the cardholder and Apple from further damages. This
includes blocking any devices on the order from further access to the
Apple iTunes and Mac App stores, and disabling all accounts associated
with the device(s) purchased on the disputed transaction.

Please provide a summary of the issue by contacting us at your earliest
convenience.

We apologize for the inconvenience and look forward to hearing from you.