Manual Paycheck Adjustments

We had a bookkeeper last year that manually adjusted the Social Security and Medicare taxes on her own paychecks while she ran payroll each week in order to increase her net pay.  She changed the amounts she paid down, to where she only paid a few cents each instead of the percentage of her gross pay that QB automatically calculates.  In later paychecks, she also manually increased the amount the company paid into both of these items on the paychecks in an attempt to get the 941 to compute correctly.  She only did it to her own paychecks.  When the Paycheck Detail is opened to review the paycheck, it shows the word "Adjusted" next to Employee Summary.  I would like to get something from QuickBooks that confirms that this was not a software glitch and was, in fact, a manual manipulation.  I spoke to 4 different representatives, 2 of whom did a remote session to review what I was saying.  I was then told by one that a supervisor would call me back.  A week later, after no phone call, the next representative told me a letter would be emailed within 24 hours.  Another week later, still nothing.  During 2 different chats this week, the reps cannot find any letter and are unable to get me in touch with a supervisor.  The best they could do was send me a link for an article on how to adjust payroll liabilities.  Not helpful.  How do I reach someone that can write a letter?