Sorry for your troubles. These devices can be finicky sometimes. Meanwhile your charging issue should either be your port on the device or the cable, rarely but occasionally it can be the plug. The reason I feel it could be the port or the cable is because these are often the locations to cause issue when charging and cause unusual behavior while charging. Your message about being connected to a charger is a symptom of either a poor connection or a crossed connection. Something is making the phone think that it is not connected to a standard plug and cable. Check your port for debris. I wouldn't go rooting around in there but you might try blowing it out with compressed air or electronic cleaner. Ports are natural places for stuff to build up due to the way we carry our devices, i.e. pants pockets, purses, car consoles. As for the cable Micro USB is a very susceptible design to damage even from normal use and not all cables are created equal. Installing the cable at a slight angle even a few times can cause the connection to become loose. This looseness then results in a poor connection. Poor connections then cause the phone to misbehave when plugged in. These issues can range from messages such as "Your device is using more power than your charger can supply please connect with the original USB" to "Your device is in USB mode" to "Your device is connected to a Docking device" and so on even when it is connected to a wall outlet. You may find that if you play with the cable or move it in one direction or another this message will go away. However I caution you to not be too aggressive in moving the cable around while plugged in because this can cause short circuits, or damage to the port. The reason your new accessories may have performed well when they were new is because the plug on the cable was new and had a good tight fit. It may have even cleaned up the port for you by being such a good fit, but over time and use the plug will become looser and a few times of being carelessly plugged in, for lack of a better way to say it, will take its toll. Only once have I had the actual plug go bad on me but like any other component it can fail, it just seems to fail less often. When mine failed my LED indicator blinked and the device would not charge. Although I'm sure there are other ways for it fail.
Your local Corp. store with service center should look at your port and clean it for free. They may also look at your cable and plug if you take them in, and they will alert you to any damage or other issues during their inspection. Of course they will also want to sell you replacements however cables are everywhere and can be found for cheap. I for one prefer to spend less and prefer instant gratification when making a purchase, so I will by the local cable at $5 or less and replace it in 3 to 10 months over buying the really expensive cable and maybe having to replace it in 10 to 20 months.