Your Google AdWords account has been permanently suspended for repeated violation of AdWords or Landing Page and Site policies in this or a related account.

[webbroi]

My client  nor I received any warning.  We even had a google adwords team optimize the account and my rep does not yet know the reason for the ban.  Not sure if its related but their google organic rankings dropped significantly at the same time.

https://adwords.google.com/support/aw/bin/answer.py?hl=en&answer=164786

Any advice here?

Do these Questions get indexed by google?  I will ask my client if I can disclose the domain.

Is there any way around a permanent ban?

They were spending 50K per month.  Is this enough to have any clout?

[DavidKonigsberg]

Your google rep should be able to tell you more then any of us about why you got banned

[ericpratum]

Barry and Ryan both make good points, and it really could be any number of things because there are so so many rules associated with AdWords. It really seems like there should have been a notification in the account or an email sent to the address/es associated with it.

Recently, I had a US-based nonprofit client run into an issue because they did not list on every page that any donations made were tax deductible, which it turns out is a requirement if your ads have anything remotely to do with donations. Thankfully, it was a very simple fix, but still, it caught us off-guard because we had not previously been aware of that stipulation.

[RyanKent]

The first issue is clearly determining the reason for the ban. The client should know the reason, but he may not want to share it. My suggestion would be to walk the client through the Google Guidelines and see which ones may have been violated.

If they are spending 50k/month, I would ask if the client has more then one Google adword account? It is a violation to use multiple accounts targeting the same words or offering the same page. Just an example but the rules are not all intuitive and really need to be reviewed.

[StalkerB]

Doubt we'll be able to tell you much without the site and since you already have a contact working on it then you're going to get better advice from them than us.

Read through the terms, make sure you nothing they don't like could possibly apply to you (be strict) and wait until your rep gets back to you.

EDIT - Assume there's no malware warning in WMT?

EDIT 2 - (since you updated the questions :])
Yes these questions get indexed.
Getting around the ban is at the mercy of Google. Sometimes yay, sometimes nay.
You'd like to think £50k a month would get you somewhere, but it's almost entirely arbitrary.

If you get lucky with a good contact it is possible that you might get an answer to what you need to change, alternatively they may just ignore you until you go away. So many nightmare stories for adwords users out there it isn't funny.