dissappointed

I am very much disappointed in the service that I'm getting from the company I app**** for finance at old mutual and they need proof of why I disputed an amount that was an over deduction in November. I requested for the letter from best debt since last week Friday and they told me that there is only one person who can grant me the letter and the statement and she is on leave will be back on Wednesday. I waited on Wednesday I contacted Carla and she sent me a letter that shows a deduction but it doesn't specify that they over deducted when I contact her she is taking me from pillar to post she cannot change the letter and needs the person that is attending to my query at old mutual to contact her. My question is how difficult is it to just add a reason for the dispute on the template .