Bear in mind that until your IVA is completed, you still owe the whole amount of your debt to your creditors.
It is also not down to Experian to clean up your record - they work on the information supplied to them by creditors.
It is up to them to clean your record up.
Sharing from experiences of dealing with debt
The greatness of a man is not in how much wealth he acquires, but in his integrity and his ability to affect those around him positively.
Bob Marley. http://kallis3.blogs.iva.co.uk
Jan's right. Unless there is a problem with your personal information there's no point writing to the credit agencies. It's down to the creditors to sort out individual accounts.