Amazon FBM Suspended

I started selling on Amazon a few weeks ago. I listed a product and got three orders in 3 days. Shipped them personally via UPS. After that, I got no order in 2 weeks even after offering the lowest price. I listed 2 other products from a single brand. I received an order and a day later, I get a message from someone pretending to be a big brand saying that my listing was one of their product and I am not authorized to sell their product and should tell them my source from where I had obtained the product. I had previously got soft approval from Amazon and since the message looked shady (they wanted my supplier), I told them that I had approval from Amazon, but if you think that is an error, please let me know and all. I got no response for 2 weeks. I believe that was another dropshipper looking for my supplier. However, that is just the basic problem. Main problem is, Amazon suspended my fbm listings saying I violated dropshipping policies and from their policies and mail, the only problem could be product packaging from a third party. Since I shipped the products by hand, that can not be the case. I do not understand why Amazon suspended my listings and what should I do next.