They look childish.I too send out cards and letters - but I'd like to think that my contact with them is much more on a professional level - I like my communication to total strangers is effective and professional.

It's a necessity to get everyone communicating!

To add to this, I ask that all communication with tenants be in group format that way there is no "he said, she said" issues. 

My brother owns a condo in the Fayetteville, NC area and recently got a letter from his tenant's lawyer stating that they have filed bankruptcy and that he could not directly communicate with the tenant until the bankruptcy was complete.  

I've met with one, but I'm looking to find one that is a bit more responsive to communication than who I'm currently using.

We would suggest constant communication and review of budget status as you go along- weekly at minimum.  

You should be able to document that fortunate accident and had other things like written communication, the lease itself, your past practice etc all demonstrating that your intent was to hold.  

I've been using the same company for five years, but the last year or so has been a steady downward spiral of bad communication, poor service, and now almost zero effort on rerents of vacant units. 

Your job at this point is to listen to your DB, stay calm, and communicate in a very businesslike manner.

Additionally: whatever you do about this, try to stick to email (other written communication) that you can later go back to in case the tenant decides to claim that he was not fully reimbursed.(1) Ask the former owner for any Lease he had with this tenant (it sounds like you were this tenant's landlord for 6 days - I'd ask for this document during the purchase period.)