You installed the pedal = your fault/responsibility. My dad's coworker bought a bike online, didn't tighten the pedals enough, and stripped them out very quickly. He had an FSA crank and I noticed the threading seemed unusually soft. They were totally gone. On the other hand, I once had an old Shimano crank that a previous owner stripped the threads on. An LBS was able to restore them in about 30 seconds. I'm still using that crank today. I would recommend replacing your crank with a Shimano unit. Like this one for example:
http://www.ebay.com/itm/SHIMANO-Tiag...item43bea777bb
Don't worry about your pedals, those will be fine as the threads are steel. The pedal always kills the crank, never the other way around.