If Amazon refuses to tell you, you can make a request under EU law that they have to honor. For example, in Germany this is implemented in Bundesdatenschutzgese

If Amazon refuses to tell you, you can make a request under EU law that they have to honor. For example, in Germany this is implemented in Bundesdatenschutzgesetz §34: You have, once every 12 months, the right to demand (and receive, for free) from any entity that stores any data about you, all data that they have stored about you, and all probabilistic models derived from it. So, you'd make a request under BDSG §34, and Amazon would have to transmit all data, including any accounts they consider connected, any and all data they based their account closure on, a list of all third parties they gave your data to, and what, and the weight factors of all probabilistic models based on you (for example, risk and credit rating models, etc).