Both bikes are entry level BSO (Bike Shaped Objects) sold at Dick's Sporting Goods.
http://www.dickssportinggoods.com/pr...uctId=17298786
http://www.dickssportinggoods.com/pr...uctId=13325217
The problem that you have experienced is not one of quality, but assembly. The problem has NOTHING to do with the brand.
If you decide to stay with a BSO instead of a higher quality used bike you would be wise if you took it to a real bike shop and have them check the build. The LBS guys love to do that!!!!!!