Opus Virtual Offices Billing Errors Nationwide

I had canceled my account with Opus Virtual Offices on February 5, 2014 and received a charge for $99 on March 31,2014 causing a $37 overdraft charge because they made a mistake and charged my account.  I have been credited back the $99 on April 4, 2014, but they refuse to correct the issue of the overdraft fee that was their mistake.  The only response I have received is that they credited it back and the bank should not charge you overdraft fees - they do not work for the bank and the bank makes their own rules. I have given the billing department at Opus a few opportunities to correct this issue without success.  As a business owner I accpet and correct any mistakes I make with my clients and expect the business owners to do the same. Mistakes happen, but how you respond to them defines the integrity of your company and I question that integrity at this time.