1998 Toyota Avalon radiator problem

Other Category problem
1998 Toyota Avalon V6 Front Wheel Drive Automatic 80000 miles

my wife hit a truck and puntured her radiator. Replaced it and started leaking at the bottom middle of radiator. Replaced it and 3 days later, same place but gushing out where pulled apart at bottom middle.
i think it is a cheap radiator from RADIATOR EXPRESS ON LINE. WE NEVER HAD A PROBLEM BEFORE. THEY KEPT MY 180.00, BECAUSE THEY SAY IT IS MY PROBLEM NOT THEIRS. DOES ANYONE KNOW WHAT MIGHT BE CAUSING THIS PROBLEM. Tried to talk to them for the last 3 months and they just rip you off and say they will let you know and dont' bother them anymore. BEWARE OF RADIATOR EXPRESS. SELLS JUNK AND DOES NOT HONOR THEIR RADIATORS IF YOU HAVE A PROBLEM.