Bajaj finance
Irresponsibility and unnecessary penalty

I purchased a computer through bajaj finance and made the payment through the cheque. some time they told that the withdrawn amount was not taken have to pay through cash and then told they were mistaken. never made the clearance of cheques timely and collect cash by payment. since some cheques bounced they told that now a huge amount has to be given as penalty. i would like to know is there any valuable rule for the penalty of bounced the cheque. please help me