2019 i was claimed dependent federal refund should be$1100 not $1800.

It appears you may be talking the stimulus payments.  If that is the case and you are filing a 2020 tax return and indicating that you "Cannot be claimed on someone else's 2020 tax return," then the full stimulus eligibility amount for you will be $1200 for round one and $600 for round two totaling $1800.

That amount would be reduced by any amounts you actually received in rounds one and/or two.  Since you were a dependent on the 2019 returns, you did not receive any stimulus payments.

Therefore you are eligible to receive the entire amount, $1800, as a Recovery Rebate Credit on your 2020 tax return.

Here is a link with more information on the Recovery Rebate Credit.