****med by Amazon

I ordered a book from them online. After few weeks of my order not being delivered they told me they don't have stock. I canceled the order and they said they will give me a refund. I never got the refund and now they are telling me I must send them all my bank statements to prove that I did not get the refund. I still don't have my money, I don't have the book and they will not refund me unless I give them all my personal financial data.