SAN DIEGO (AP) — San Diego Gas & Electric will refund $51.6 million to ratepayers and pay a $5.5 million fine over a botched program to encourage people to buy energy-efficient lightbulbs.

The San Diego Union-Tribune says the California Public Utilities Commission on Thursday approved an agreement that SDG&E reached nearly a year ago with two consumer organizations. At issue was a utility program to get customers to buy energy-efficient lightbulbs by providing incentives for manufacturers and stores to provide them.

Investigators found that SDG&E couldn’t account for millions of bulbs, some of which were overstocked, never sold or never delivered.