After the dealership replaced the battery and capacitor, none of the blinkers are working. I replaced the 25A fuse for the hazards and verified that one of the four bulbs were still intact.
I checked the engine fuse box as well as the cab (ankle level) fuse box and couldn't find a signal relay.

Any thoughts here from the experts?

 

The obvious is to return to the shop that serviced it and have them double check their work. Because it is electrical and can affect other parts of your Mazda and clearly because you are asking how to diagnosis an electrical issue maybe this should be attended to an Auto service mechanic or Technician?