My contollor will no longer charge. Any advise?

Do you have a meter to check the output of the charger power supply ?  
The charger is fused, so first off I would check/change that and obviously use/change power sockets/wall outlets etc.
And ensure the mains plug end cable is pushed firmly into the power unit/transformer, could be loose.

Pays to check the simple things first on the off chance.

Hi, we're sorry to know about this situation. May we know if you're using the charger that comes with the package? If the remote controller would not respond to the charger, I would recommend sending the unit into our facility for further evaluation of the unit. Repair fee would depend on the warranty of the unit and the outcome of the evaluation. If you wish to contact our support. kindly visit the link below for your reference. Thank you for continued support.

www.dji.com/support