Then save up your reserves for future deals.

They did not reply for 5 additional days and when they did, they demanded full rent payment and sent us receipts for the appliances they bought and the cleaning services they used prior to us moving in. 

Don't forget that you need cash  reserves and closing costs in addition to the down payment. 

I was wondering if you use any tools/services to manage your fix and flip projects?

I say this because with 20k your options are fairly limited and you need adequate cash reserves to properly do REI. 

Is this a service all GCs offer and what is the cost?

I have been to a few auctions with other Rental property investors and most auctions have a reserve which has to be met for the bank to allow it to be sold.

Apparently the database they use can't export lists to excel or csv so they forward my message to the software company and they sell it to me as a service...

Sears scratch and dent seem to be the most competitive, and to your points will not carry much weight in terms of warranty / service given the struggling brick and mortar model. 

This is a bit of a public service announcement.