In your pre-prepared interview answer you should include the following:

☛ I listened carefully to what the customer had to say.

☛ I apologised and empathised with their situation.

☛ I confirmed my understanding of their concern.

☛ I took responsibility to resolve the issue.

☛ I offered a solution (plus alternatives if possible).

☛ I confirmed the customer was happy with this.

☛ I thanked the customer for raising the issue with me.

☛ I took immediate action following the call to resolve the situation.

☛ I remained calm throughout the whole process.

☛ (If appropriate) the customer wrote in to my supervisor congratulating me on my efficiency.