incorrect...
you register an account, you click on rent... a second time that you are willing to pay... thats it...
That doesn't make any sense. The FAQ says this:
When do I get paid?
24 hours after the end of the rental.
Your renter has paid the full amount to Betarigs before the rental began, and if the mining job was done correctly (basically your rig was online during the whole rental), the payment will be transfered to you 24 hours after the end of the rental period. This 24 hours delay is to give time to your customer to file a ticket if he wants to claim a refund.
Note: If your customer indeed submitted a ticket claiming your rig was offline, payment for this rental will be put in hold until the ticket is processed.
Edit: Oh, I see what is happening. They are clicking "Rent" and then they have to actually forward the BTC to Betarigs. During this time, your rig is "locked out" waiting on payment so if they fail to do so, you are stuck in limbo.
Again, I'm new, but I think the simplest solution to this problem is that you have to actually forward BTC to Betarigs BEFORE you are allowed to rent a rig. So, if you have a zero account balance with Betarigs, you cannot rent. This would take care of the problem of people attempting to rent rigs but not following through on payment.