not 100% sure, but I think in 2011 they stopped letting people piggy. Definitely do not quote me on this though. Really interested to see if anyone knows this answer for sure.
Don't quote me on this either, but for bad credit, quickest route as far as i know is send out disputes and get a secured card for like $300 but don't exceed 20% ($60) of credit.
It sucks, tedious and takes time
for disputes, either use a reputable company if you don't want to take the time to write all the letters yourself or check this book out, he explains it very well and gives templates on what to write.
http://www.amazon.com/dp/B008XBP120/?tag=cl03f-20hope this helps