you are an advocate but you have given blank cheques for repayment of loan
2) section 138 NI is attracted on dishonour of the cheques
3) when you issue blank cheques you authorise drawee to fill in the details
4) There is presumption that when cheque is issued it was in discharge of debt due and payable
5) there are judgments that when blank signed cheque has been issued by the drawer he authorises drawee to fill in details as to name , amount and it does not amount to material alteration of cheque
6) excess cheque amount attracts 138 NI
7) Supreme Court in Kalyani Baskar v. M.S. Sampoornam held that every possible assistance should be offered by the court when an accused in a complaint case seeks directions to refer a disputed cheque for the opinion of a handwriting expert. Supreme Court held that where a cheque was doubted as to its authenticity, the trial court ought not to refuse the request of the accused sending it for the opinion of the expert.
8) you have not mentioned how you repaid the loan amount . if it was by cheque bank statement would refelct repaymen tof loan
9) you should have made application in trial court to seek CFSL report on the receipt if complainant denied his siganture on the receipt