Debit order bounce repayments

Hi ,I have changed the job from one company to the other and the pay date was changed as well ,I have notified Old mutual finance for the changes and that was never been changed in their system ,I kept on calling and every would assure me that it has been changed but i had the debit order bounce everytime because the date was not changed and the cost was accumulated in my account ,i have addressed it with OMF and they asked me statement that i provided to them,They came back to me again asking for bank statement again ,I really dont know what else they wanted ,I need some assistance ,The debit order bounce charges for the months i have escalted this and the bankstatement charges that i have withdrawned to provide to them ,<br> I need assistance ,I have provided everything they wanted ,I dont know what else must i provide .<br> Please assist me .