I was charged twice (standing order, THEIR mistake!) for my October monthly satellite service (Tooway 25GB/month) I'd been subscribing to, here in Spain, for a bit more than a year.
After noticing it, I sent countless support tickets, that all went unanswered. I spent more than €/£10 and 25 minutes on the phone with UK support on 12th January 2018 to sort it out. Most of my time was wasted listening to waiting messages.
Three months after my first support ticket, and two weeks after finally being told by the Finance dpt that I would be refunded shortly, still nothing.
The people I talked to were pleasant, but the follow-up is appalling.

Update: refund credited 1st Feb 2018, 4 months after their mistake and 3 months after my first support ticket.