Citibank Credit Card Complaint

Citibank Credit card department,

Credit line increase/decrease Maryland

WELL, MY ACCOUNT WITH SEARS CITIMASTERCARD WAS OPENED BACK IN 2013 WITH AN ORIGINAL CREDIT LIMIT LINE OF $5000.00. NOW, FOR REASONS UNKNOWN OR FOR REASONS OUT OF SPITE OR DISRESPECT, MY CREDITOR JUST RECENTLY LOWERED MY CREDIT LIMIT LINE DOWN TO $4200.00?! NOW, WHAT THAT MEANS, IS THAT CITIMASTERCARD WILL CONTINUE CHARGING MY FEES FOR BEING OVER THE LIMIT AT NO FAULT OF MY OWN!! UNLESS I FILE BANKRUPTCY? I TRULY BELIEVE THAT CITIMASTERCARD ENGAGES IN USARY & CHACANERY & FRAUD!