1. You can not claim interest unless you have proper license to lend money against payment of interest from RBI,
2. Moreover, you can not claim 4% interest i.e. 48% interest per annum,
3.You can say that you had lent him some amount against payment of bank rate of interest which you will loose for not keeping in the Bank,
4. While claiming that you had lent some amount (may be more than Rs.28 lakhs, you shall have to prove that you had that much of amount which you had withdrawn from the Bank and/or arranged from some source),
5. Do not show that those cheques are security cheques since sec.138 of N.I.Act is not applicable on security cheques as per recent judgement of the Supreme Court,
6. Now you fill up the cheques with current date and deposite with Bank,
7. When the cheques are dishonoured, take appropriate action u/s138 of N.I. Act,
8. You can also file a Recovery Suit claiming return of the said amount lent with interest, damage and cost,
9. You can also file a criminal case of cheating you by not returning you the amount taken from you even after promising.