surety in bail

Im surety for Rs 50000/- in one of my friends bail application,

Unknowingly I encash that FDR .. without giving the FDR in original to bank, the original FRD on which court stamped still with me .

Now I want place a application in court that i want to change the FDR of same amount taking plea becasue I get better interest rate in new FDR,,,

Is that correct,, or is anything wrong in it,,

Is there any problem on my friend,who is on bail.. or any problem on me being surety.