Only recently Apple had a wall plug adapter exchange programme,now they are back again with a USB-C Cable replacement programme.
Apple sate
A limited number of Apple USB-C charge cables that were included with MacBook computers through June 2015 may fail due to a design issue. As a result, your MacBook may not charge or only charge intermittently when it’s connected to a power adapter with an affected cable.
Apple will provide a new, redesigned USB-C charge cable, free of charge, to all eligible customers. This program also covers Apple USB-C charge cables that were sold as a standalone accessory.
For MacBook owners who provided a valid mailing address during the product registration process or Apple Online Store purchase, Apple will send you a new cable by the end of February 2016.
All other eligible MacBook owners should use the replacement process below to receive a new USB-C charge cable.
For more info and if you think you have been affected see HERE for the full details