Back tail lights don't work

I took my 1993 Toyota Camry Wagon in yesterday and they replaced the back tail light bulbs. When I got home they did'nt work again. I took it back down today and they said it needs a tail light relay switch for $394. I stopped at Advance Auto Parts and they have one for $61. The service manager thought the relay was in the drivers side back panel. The guy at the parts store thought it is under the dash. Any idea where the relay switch it is located. I'll be more than happy to donate with the correct answer. Thank You, Paul