regarding relieving from duty nd putting salary on hold

hello i am swapnali.. m 23 year old mba student... m working as wel studying.. as financial problem .. and I am only earning member in my famly as my dad is retired my brother is studying ... so from last 2 years m working with a xyz bank.. but not on payroll.. it is a third party payroll... recently I got new job vid gud package.. before trying for new job I asked my consultancy company about notice period they told me 7 days is our notic period... so I inform my new compny dat I vil joine yu within 12 days... nd I put my resignation mail to my manager in bank.. he said 7 days not possible .. extent some days.. so I contact to my consultancy company dey said our notic period is 30 days sumone give yu wrong information... so I discussed vid my new compny about extension... nd I again put resignations mail to bank with 15 days notic period... den my manager says vil not relieve yu, yu need to hand over yur work to someone ... I said ok I vil training to the new person ... den they was lyk v r not getting anyone so yu arrng sum person for yur plac after dat v vil relieve yu.. otherwise yu vil not get yur experience letter nd april months salary ... I put my regisnation on 22nd april nd my last day vil be 6th... so vot vil I do if they put my salary on .. my salary amount is 13500 nd salary date is 7th pls help or advice me 13500 is big amount for me