Amazon India — states on my bill amazon mktplace pmts/bookstores

Address:

78006

I have been charged on my american express card for an item that i did not purchase. It is for the total amount of $50.64. I don't know what the item is, is it books, accessories, or other? I have an item posted on my american express dated (September 15, 2017) 09/15/17 that states "amazon mktplacepmts/book stores. Can you please let me know what the item is and the model number etc if appropriate. Please get back to me as soon as possible. Thank you. I enjoy working with amazon and i don't want this to make me us both unhappy. Thanks again

I have no idea what this is? Books? Other? I don't know