Rear Suspension Springs problems of the 2012 Toyota Tacoma

In may of 2017 the left rear leaf spring broke I proximity to the gas tank. I was told by heritage Toyota that there was no recall in place for 2012 Toyota Tacoma pick-ups although a recall was in place that stopped at 2011 vehicles. I had both sets of rear springs replaced as a precaution in may of 2017 at my expense. As of last week. A left rear spring has again broke in the vicinity of the gas tank and I am again being told that there is no recall in place for 2012 Tacoma's. This truck does not get heavy use or carry heavy loads although I do live on a gravel road. I am having a hard time believing that this repeated problem is not a manufacturing or design defect with a real safety concern given the proximity of the broken spring to the gas tank. The defect was noticed while driving due to a loud clunking sound coming from the left rear of the vehicle.