Please provide more information, and supply log files as what you're describing isn't possible.
If your client crashed, your session would stay active with RuneMate's servers for a maximum of 30 minutes, meaning an overcharge of 1 hour (if you were the majority of the way through an existing hour's session). There's no way it could have continued in the background for $7 worth of credits. Even if you were running a bot that cost 20c per hour, this would mean an overage of 35 hours to consume $7.00 worth of credits.
Respond with:
Screenshot of sessions page (even if empty)
Name of bot(s) you were running when crash occurred
Log files -
A lot of users ask how to view the bot logs and send the right ones. How to find your logs Step 1. Open the RuneMate client and navigate to the toolbar Step 2. Open the "Help" menu and click "View Logs" (see Figure 1) Step 3. Sort by "Date modified" so you're looking at the most recent logs at...
www.runemate.com