It's interesting you say this because for some time people in my family were using Amazon's excellent customer service to make money by fraudulently lying about misdeliveries and product conditions. From what they told me customer services reps at Amazon basically ask no questions (unlike other stores) and would happily ship you multiple high-value items. Apparently you'd have to be strategical to not make it look too suspicious, but if you can get serval households involved you could get a few new phones for free over the course of a year.
This was for higher value items though, and maybe Amazon's customer service / returns policy is different in the UK, but I'm genuinely surprised that you avoid Amazon for returns because from what I understand they're far more likely to accept a return than other retailers.
I think I probably have a biased perspective because of my background, but 99% of the time when I hear about someone returning stuff they're doing it fraudulently. That cost is then passed on to people like myself who basically refuse to return anything unless I'm sure I'm 100% not at fault so in general I wish companies didn't do returns outside of exceptional circumstances. Also working for a phone insurance company and a retailer with a relaxed returns policy made me appreciate the insane level of fraud which has to be financed by honest consumers.
But on the topic of in-store returns, one of the only times I've ever returned anything was a pair of £60 shoes which tore in the first week of normal use. I went to the store I brought it from and explained they tore and would like a replacement. The staff were extremely rude and tried to blame me which I found very uncomfortable. They then said they'd have to ship it to some department to assess if it can be repaired or replaced. A couple of weeks later I got a call saying it was decided I was at fault, so no replacement or refund would be issued and that I could come collect my shoes from the store. The store was about 30 minutes away from my house and I had to pay for parking, so this was all extremely inconvenient.
Maybe it's just because I have social anxiety, but I'll take cheerful chatbot over having to deal with a rude person instore any day of the week. In fact, it's why I use Amazon. Their customer support has always been great for me.