I left them recently like many others have in the last 5 months and even though our money was technically an investment and a limited partner contribution, they refused to give anyone their money back even after stating numerous times they would give people their money back if they choose to leave. 

Just underwrite a refinance assuming about 30-36% of the money you will receive goes to refinance closing costs at worst, and find discounts when you can.

If you didn't actually get any money, how do you know for sure they are a real legit lender? 

Also CA requires you to be licensed to originate DSCR and Hard Money Loans (I see on your bio you service CA), and there are many other states that are starting to follow pursuit.

Keep saving money. 

In the end, it may be the same amount of money or more, but it will just have to be structured differently as you navigate the shifting market.Northwest Valley would be a good option. 

Trouble with cities on permits?

I am a hard money lender and need advise if an unsecured loan I made through the Solo 401k defaults and is uncollectible are there tax write-offs as a result of the uncollected loan?

This is the scenario:I buy a fixer with some hard-money.

You can save a lot on costs if you do many repairs yourself.Look into hard money lenders or private lenders for the initial purchase and rehab.Connect with wholesalers, agents specializing in investment properties, and other BRRRR investors to find deals and learn more.