It's actually normal! Sadly companies seem to be "send it in NOW" but then take their sweet time processing the information. Give it a month then chase.
Last Payment made 04/12/14. Completion Certificate 25/7/15. IVA company GT. No Issues
Standard terms and conditions give them until 2 months following the anniversary date to produce the results. 10 days (7 working days) is but a blink of an eye.
My opinions are merely that .. opinions based on experience. Always seek professional advice.
IVA Completed 23rd July 2013 .... C.C. 10th January 2014