The listing agent told me to include an invoice form of repairs with my offer under asking. 

My insurance agent said they sent them an invoice but haven't heard anything back.

It is common for vendors to invoice us 2-4 weeks after work and then we issue payment in roughly 2 weeks turnaround so most of our bills don't process through to owner statements for 30-60 days.

Upon accepting the booking/creating invoice, I use the calendar on my phone to set the second payment due date with a reminder.  

Any expenses should be backed up by a receipt or invoice.

Always use a pro, and always ask for their opinion on cause when they invoice.  

If you hire the tenant to do something, ask them to send you some sort of invoice (even if just an informal email saying what they did).

You can also write them an email explaining the fact that you will not pay any invoices that don't have your approval.

Make sure that you take pictures of every appliance, have them listed in the lease as part of the house, and keep receipts or invoices.

The issue is a civil matter and the tenant will either need to consult an attorney for any damages they feel they incurred or file a complaint with the housing department in whatever government agency has jurisdiction oversight for housing in the area of your property.fyi, should you get an invoice for a "hotel" bill send a reply with a copy of their rental agreement or lease asking them to identify where it states they should be reimbursed.