Incorrect billing for existing customers

I've been a customer since February 2017. I've always appreciated Home-Connect's pricing and their "uptime". I recently found out that I've been incorrectly billed for at least 16 months.

I noticed this when I checked their pricing on their portal and this pricing was different to the package I am on. I would assume this infringes on the customer protection act.

I was notified that they would update my billing for the next billing recurrence but damage has already been done for those past 16 months with no compensation at all.

If you are an existing customer, I implore you to check what you are paying vs's what's priced on their website.

This discovery has made me look into new ISPs.