Ethical actions and material irregularity

Having twice failed to set up an IVA because my company was able to block the IVA by virtue of the % of value owed, and on both occasions having dealt with our solicitor the well known practitioner firm  acting for the debtortried a third time and avoided the solicitor sent the paperwork/notification of the creditors meeting to a then no longer trading/conducting of  business at address and because the redirect postal arrangement had ceased the IVA Creditors meeting proceeded without our knowledge. Some months later the notification was sent to us. Two months later and after being asked, the practitioner finally provided details of the outcome and process. We are still within 28 days of finding out and have asked the practitioner to set aside on the grounds of material irregularity. We anticipate that the practitioner will ignore our request and we will then be faced with a significant legal bill to challeneg the IVA. Is this "sharp" practice and do we stand a reasonable chance of success if we challenge and the practitioner refuses to comply with our request? The action of the well known practitioner gives rise to a consideration of reporting to the professional body.