Citibank Credit Card Complaint

Citibank Credit card department,

Credit line increase/decrease Pennsylvania

I applied and was awarded a Sears Citi Credit card in - 2013. They approved and awarded me a credit limit of $6000.00. I have paid consistently without incident. Now they have dropped my limit to $4800.00 which has impacted my credit score because I owe $3800.00. So instead of being $820.00 away from be 50 % below the limit the credit limit keeps getting reduced as I pay the credit card down. So my credit score is lower then what it should be due to no fault of my own. Please request that Sears increase the limit back to $6000.00 as originally agreed. They do not have to permit or allow any future charges, but I want my credit score to increase by having them maintain our original agreement. Thank you for your assistance with this matter.