Charger won't work on a iPhone 5C

Well basically I went to the shop and brought a 5C. I turned it on for the first time and set it up and everything. Then I noticed my battery was at 21%. So I connected it to the lightning cable then I had a notification 'This accessory will not support your iPhone'. So I tried it the other way round, I still had the notification. So I just thought it will charge later so I left it on overnight. Zzz. Then I checked my battery status: 17%. So I brought another charger and I STILL had that bloody notification. I got a bit p*ssed then. So because I was so bloody angry I didn't bother going to the shop I brought the phone from, I went to the Apple store and asked them to 'try' and charge it. They said it wouldn't charge. So I was a bit more p*ssed now because even the Apple store wouldn't be able to fix a phone their company made.