obligations and contracts 2

Tanong ko lang po if anu po maganda gawin since last march, 2012 i was receiving a demand letter from a bank who offered me a salary streched loan. my loan was grant and had a principal amount of 200k,and they ask me to sign blank cheques under their bank for 36 months. Was able to pay monthly naman po until a financial problem arise and not able to pay since then october 2011 up to now and the principal left 181k. Now there this lawyer na affiliated daw po ng bank and who uses an spo3 santiago to call the office and mentioned to my staff regarding an estafa case filed against me and leave a message na may warrant of arrest daw po na nakapending sa kanila and inaadvise na ipapadampot ako sa office. Now para maiwasan daw po yung move na yun tumawag daw po ako office ng complainant which is attorney Ranny Palisoc. frightened and paranoid of such message I called their law firm and advised me to issue a post dated check under my name kasi may obligation went up to 595k na since 9 months na raw po ako di nakakabayad. Now they said i need to pay on june 19 an amount of 81,770 and on june 30, 2011 another 81,770 or else a writ of execution will be filed against me which i beleive a civil case. Confused of their statement i did not send a pdc check as requested. Dahil unang una i know if mag send ako ng pdc ng amount na yun hindi ko po ito mapopondohan dahil wala nman po ako ganung kalaking pera. And now nag threat nanaman po cla na drastic measures will be don since di ako nakikipag cooperate. My question is anu po ang pede nila gawin sa akin, 2nd can they really have me arrested in the office? Please advice.

Additional to that this spo3 santiago said na they were advice of shoot out order if i will not cooperate... Which i mentioned to them and they denied na they dont hire goons, but i said it was being said by that sp03 santiago.

i know i have an obligation to fulfill and willing to re negotiate however they are very strict and states that wala na raw po magagawa dahil nag breached na raw po ako ng contract. kaya i need to pay and instead issue a pdc check of my own and date such according to the above sched. But i did not heed to issue such kasi masyado po mabigat yung scheme nila and i cn't find that money in less than 20 days. Please enlighten me.. estafa or criminal case po ba yun?