Which stores in Cardiff that sell Noice Cancelling Earplugs?

Hello, so there is too much noise in my house every night so I can't sleep, I have already told these people but they don't listen. I am looking for ear plugs not big headphones, that cancel out noise completely. It should not just be slightly muffled or anything, it should block out atleast 90% of the noise. So they need to be very effective.

However, they need to be under £10 please, no more than £11.

I can't order online, so are there any stores that sell these in Cardiff City Centre? I have already tried Wilkinsons, Argos, Asda and Tesco's.

So does anyone have any other ideas. I know I have a very thin margin but please bear them in mind when answering my question.

- Block out noise very effectively

- Under £10,

- Physical store (not online) in Cardiff City Centre area

Please someone reply because I am losing so much sleep.