Bad service overall in updating report

I called Experian wanted to enquire about sending a paid up letter through from one of the listings that were listed on my report twice. The guy in the call centre advised me to log a dispute that will take up to 20 days which is unacceptable to me because I have already went through this with Transunion. Yes I know they are not the same company but really. Nedbank send the proof on their letter head to remove it so what should be so difficult. I cannot wait another month for things to be sorted out.