Divvy overbilling?

Has anyone received excessive credit card charges from Divvy, even after returning the bikes on time and waiting until the docking station showed green? Today I received my credit card statement with a $102 charge for checking out two bikes for no more than 15 minutes.

On the day in question we returned both bikes at the same docking station only a couple blocks from where we found them, and made sure the lights were green, but the Divvy rep claimed that one of the bikes had been out for 43 hours (!). Supposedly they will refund me, but now I'm wondering if there've been other similar spurious charges that I've missed in the past. How common are these errors?