AI render credits; How did I run out of 1650 credits in x1 week?

I started to use Sketch ups plugin 'AI Render' which is Nano Banana merging with sketch up. I was really enjoying it so I subscribed to 1650 monthly credits as I quickly ran through the free version.

1650 credits....now I would think that equates to 1650 rendered images? I have only been using this plugin for x1 week and probably use maximum 10 rendered images a day, a mix of images not rendered properly and some I can actually use. So how on earth did I run through this so fast?

I am so disappointed as I thought this would definitely last the whole month.

Can someone explain how this works?