Online feedback surveys that are incredibly long. I'm not saying the company I work for is perfect in any way, but our customer feedback survey is short and snappy because we felt that we'd be more likely to get replies.
However, pretty much every feedback survey I get is stupidly long. I've just had one from M&S in relation to a recent click and collect order. It wasn't that good and I've got a few ideas to improve the process, so I clicked the link in my email. However, I'm told it'll take 10 minutes to complete and they start by asking me a load of questions about my lifestyle/what I enjoy doing.
I lasted the first page (one of those where you have to rate things) but when the second page loaded and it was longer than the first (plus it told me I was 25% complete) I just closed it. They weren't even offering an incentive to complete it.
I just wonder how many staff were involved in making that survey and seemingly not one of them thought "hmm maybe the average person doesn't want to spend at least 10 minutes on a feedback survey".