Shrinking school uniform

[var123]

Aibu to think that school uniform isn't fit for purpose if it shrinks badly in the wash?

My dcs (state comprehensive) school requires logoed sports kit from the school supplier. The top costs £31.99 plus about an hour of my life in the queue this week!
Last year, on the advice of the shop, I bought ds1 a really big size so that it would last a couple of years.
The label says wash at 40 but I usually do things at 30.

Yesterday I realised that ds1 has completely grown out of the top. He couldn't even get his arms into it. He's been on a growth spurt so I thought nothing of it. However I happened to be sewing labels into ds2's brand new kit at that moment so I asked ds1 to try it on for size. It was a good fit.

Then I looked at the size labels and they were identical, except ds1's top has massively shrunk. It's 4 inches shorter around the chest and two inches off the length and arms.

I realise that I don't have a leg to stand on a sits a year old, but I don't think it's fair to have to buy clothes that will shrink so badly. Sale of goods act?

What are they made of?

50% cotton / 50% polyester

Label says machine wash at 40, 2 dots iron an 1 dot tumble dry. I haven't washed it very often, it gets line dryer and I'm a bit too lazy to iron it when I know it will be screwed up in a pe bag so it's probably only been ironed once or twice.

Autocorrect on my phone but hopefully you get the jist!

I would complain, but I wouldn't rte your chances of getting anywhere with it. The problem is you can say you followed the instructions for washing, but can't prove it. However, it may be there was a dodgy batch and lots of other complaints.

I think you are right about how the shop will respond. Tbh I would have just thought that it only seemed small because ds1 had grown if I didn't have another one in my hand at that moment. So, I doubt that there will have been many other complaints as other parents will probably just think their children have grown out of it.

That's the trouble with pe kit - you don't usually see them wearing it.

I was thinking to buy another (because I have no choice) but to show the shop the shrunk one when I go in and ask for a guarantee against shrinkage for the replacement? Writing that, I can see that the shop will refuse.

Or just buy one that would fit a medium sized man and hope it shrinks to fit ds???