Just moved to the Netherlands, having been before, and stuck with the same provider. The first month went great but when it came to topping up, I put €20 to make sure my data bundle renews and gives me credit for calls.
The website states the data renews if you have the credit on your phone so naturally thought I was fine - 2 days after topping up, my balance is€0.00. I called customer service, they stated it hadn't renewed and I was charged €0.50 per MB, and was told my only options were to pay more, or just switch to a different provider. Really shows how much they care for their customers. I'm obviously opting for the 2nd option.