Don’t buy stuff like electric blankets at Builders

Bought an electric blanket in winter, and after 4 days it seemed like only a small piece of it was still working (getting warm). Put it back in its bag and actually forgot about it for a few weeks, but eventually took it back for repairs in a hurry. Today I went to fetch it again, very happily thinking it’s fixed, just to find out after I waited there for a good 20 min and was ready to sign it off, that they find absolutely nothing wrong with it. So what must I do with a quarter-working electric blanket — give it to my dog? If they told me this over the phone already, I would not have put in the effort and wasted my time collecting the thing, you could have just kept it or chucked it in the bin. I don’t want a refund, I am also not going to waste my time going there with the blanket again, I just now know that Builders is not the place to buy these kinds of stuff and I would not suggest anyone else to do so.