HMRC bullying and Harassment

We have been given a VAT assessment which is highly inaccurate and the VAT man is making this a personal vendetta by not allowing or workng with any accountant I appoint to resolve the issue.

They have entered the property to take reports by threatening my partner and staff when they were not in and now claims that partner was in. He has been very aggressive when he is dealing with my accountants and he has had other information about both me and my partner through other departments which has made his judgement against us as such we have not been treated fairly. Does anyone know where we can go to harassment and unfair treatment by HMRC staff? Has anyone taken on them on for these type issues?