Welcome to the forum ... Whilst in an iva you are protected from those creditors who form part of your agreement. If you are receiving phonecalls from them then simply inform them if your IVA and direct them to your IP. If you are receiving letters then direct these to your IP.
You may still get annual statements from your creditors but these can be ignored once in an iva.
Sharing from experiences of dealing with debt
There is a solution for everyone .... Just need to stay positive !