last im gonna say on this. An issuer like Citi can be worth tons in the future more than what you lost here. I am extremely doubtful anything good will come of you harassing them.
if you are sure you are blacklisted, then why continue? Even after 5 years, there are some people that cannot get Citi cards b/c of a previous blacklist. Some can after 6 months, others 2 years. Which one are you in? Unknown. What puts one person into a longer category versus another? Unknown. Catch my drift yet?
try to have a bit longer of a time frame in mind. 1 hard inquiry is a pittance.
do whatever you feel comfortable with.