Logitech MK550 Wireless Keyboard and Mouse

I order the Logitech MK550 Wireless Wave K350 keyboard and mouse combo after several reviews. The ordered it in July and it took a month to arrive. I happy to receive the keyboard that was shipped inside an amazon box. When I opened and hooked up the keyboard it was very easy. However, once I went to use the keyboard I discovered that on the number key pad that 0,5,7 do not work. I went back and looked at the box the keyboard came in and noticed tape on both ends of the box, I thought was part of it being packaged. I have now decided that it was defective and returned and Amazon just shipped the defective keyboard out instead of pulling it from the inventory. I am now on an hour + wait phone call with Logitech to see what can done about the defective key pad. I am extremely frustrated that it took Amazon a month to get the product to me and the return window was only 3 weeks. Amazon took so long to deliver the item, you would guess it was mailed directly from China. Because the order was delayed, I was closing out the year and I am just finally getting to hooking up the keyboard, which quick and easy. Unfortunately, the key pad is defective! The return window is now closed! I am not impressed with Amazon product support and their VERY L O N G slow delivery!!!