Not a secret, often overlooked:
"Keep your promises."
If you say you'll show up every day at 8 am, do so. Every day.
If you say your service is excellent, make it so.
If circumstances or priorities change, well then, invest to change them back. Or tell the truth, and mean it.
If traffic might be bad, plan for it.
Is there actually unusually heavy call volume? Really?
Want a bigger brand? Make bigger promises. And keep them.