We used them recently and they were brilliant. We called in the morning, thinking they would be taking a day or two to come and collect, but they came that same evening.
I have called them a few times since our move and they have showed up everytime picking up loads of stuff that I can't find a place for in the house. Have been very reliable. Google Take My Junk and number should come up.
I have used them during one of their busy periods . They do come but at that time it was a bit of task to sort out an appointment as DH wanted them to show up in the evening , by which time their truck use to get full already(they start collection from morning all they way until truck fills up) so they were finally able to pick up after 3 tries. I am sure it's not a norm. Their number is mentioned on their website. Google take my junk. They even respond on what's app. It was a relief to get rid of our fridge and spare mattress with minimum hassle.