Welcome to Just Answer. I am here to help you resolve your tax and finance concerns. Please feel free to ask anytime you need extra help.
Here is how I see this:
Monthly income Pension 1830
Tax return (assuming single, no dependents - anything else will be better for you)
Pension income 21,960
Taxable SS 10,080 (1/2 taxable)
Total Income 32,040
Standard deduction -5,800
Taxable income 22,540
Tax 2,960 (from tax tables)
Est for state 987 (1/3 of federal)
Total tax 3,947
From this subtract any tax withheld and you will have a ballpark refund/owed amount.