Hi Brooke - I wouldn't worry about how and when the creditors receive their money. As the others have said. they know only too well how an IVA works.
Please be careful about coming out of your IVA, as has already been mentioned the creditors will start charging you interest again and you could end up back to square one.
Chase your IP for a response from your review - email/phone him direct.
If you are still worried after your annual review, come back on here and we can advise further.
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