its really hard.. but i think it is a web URL

no its not a web url its a something like a coding
is anyone got 0.1 btc for solving answer ?
It is a web URL.
The code is:
A=B B=A C=D D=C E=F F=E etc.
it ends up here
http://i.imgur.com/ivBbFcn.pngnotice the number 6 in th corner? Now find the 6th apostle. What's their name?
Answer is in bold above.
Lol.
I was doing something completely different to figure out the address, and I got all the way to
http://i.imgur.com/-------.png. I just couldn't figure out the filename.