Have you had good experience with doing hand written letters at all? 

Welcome.The first letter in the real estate investing alphabet is "C" for Cleveland and Cashflow.I'm not here to sell you on Cleveland.

Get an attorney to write a letter to the credit card company with your appeal. 

Also, consider the lenders lending options as some will require interest only monthly payments for the period that you have he loan and others will set you up with a balloon payment. 

Check that the information is accurate, then try again.There are many websites where individuals can purchase fake credit reports, pay stubs, letters of hire, etc. 

You could do a letter or something not much time and cost to see if they bite.

Now that we a vacant home I can’t find any official Letters.  

I have an opportunity to by a 6-unit property for $300K with a $240k Commercial loan and a Seller carry back of $60K at a 6% interest rate with a 5-year balloon. 

We have discussed Sellers Financing with a 2-3 year balloon, i just don't like all the liability being on me and it not being though a bank and just a contract, if god forbid something happens to be at the end of the balloon ,then my family would be in a pickle they couldn't just sell the building to help with the financial burden, and would have no use for the building if I'm not there working.

I finally received a demand letter from a "nonprofit attorney" representing the tenant, claiming that the tenant was living in uninhabitable conditions—typical for a non-paying tenant, I guess—and now she wants to "renegotiate" the rent and keep living in the same space.She has been filing complaints with various government departments, but all the cases were minor and have been closed.