why same number repeated in creit field in report

ahmedba

I have report found in this link:

http://www.mediafire.com/file/ipgkmlkj0 ... output.rar

as you see in link above there are duplicate value one value found in debit and same value for credit this report about customer statement(number id 50078) report and i take screen shoot to problem already attached with this report

as screen shoot above for customer je-tc-2042 he already debit with 15000,25000 but this number repeated again in credit field after he make post

why this problem made the users enter the value one time but repeated two time one for credit and one for debit