My calculation says that you could have used a maximum of about 150wh until the first bar went on your display if everything is set correctly. For 60 miles at an average of 12 mph, that would be an average of 30 watts from the battery, or 21 watts of actual help.
The first thing I'd check if my battery was showing full on my LCD after 60 miles is whether it's set to 48v or 36v, and if it turns out that it's set correctly, I'd be looking to save weight by removing the electric kit. I know that when I ride my road bike, the effort is about the same for the same speed as on my electric bike on level one using about 50w from the battery or 35w of actul help. That's at an average speed of 14 mph (hilly).
The LCD should have automatic voltage recognition between 36v and 48v, but I know that if you fist connect a nearly flat battery to some LCDs, the software wrongly interprets the battery voltage, so you have to disonnect the battery and reset the LCD before reconnecting to a charged battery to get it right.
If you're using that little amount of power over a journey, the small amount of help you're getting will be cancelled by the extra effort you need to get the bike up any incline. You've added about 7kg mass that will require approximately 7% more effort to move the bike on any sort of incline at the same speed as without the extra 7kg.
There is no magic with any electric bike. Yes, it feels like there is, especially when you first get one, but it works according to the laws of physics. There is energy stored in the battery. You can use about 70% of it if you're careful, and you can use it to get a tiny bit of help over a long time or use it up much faster and get more help but for a shorter time, or any combination of those scenarios.
Whatever range anybody gets out of any battery with any motor is determined mainly by themselves and their circumstances, not so much by the bike, and hardly any difference from the electrical system in normal circumstances. Speed has a very significant effect on the power needed, and streamlining (drag) makes a big difference when you're going fast. Neither of those has anything to do with the electrical system.
I guarantee that I can get a range of 200 miles out of any normal electric bike that you put in front of me.