GLS is the worst delivery service ever

For the last 3 days I've received an email in the morning saying that the book will be delivered that same day. For the last 3 days I've seen the truck's GPS tracker crisscross my town, driving just past my house. For the last 3 days the day ended with no delivery, no explanation and no apology. The contact line is absolutely useless, they can't even get in touch with their own driver. Shameful service.