Dispute on Credit Report - Duplicated Loan

Experian SA has the worst customer service ever. Each time you call you wait for 30 minutes plus and still do not get your issue/dispute resolved. When you get hold of the consultant they tell you to send an email and wait 48 hours for the matter to be attended to, that time I am requesting for them to rectify the error (duplication) they made. If your email of dispute is not in the way they want they tell you to resend and you wait another 48 hours, and not get a call from them, you have to call. It's been 7 days now trying to resolve this, as we speak I was on the line for 35 minutes, no one answered and the call got cut off. This is holding back an application that I am trying to do with another institution, I can't do anything until they correct the credit report. Demoralised.