Cheap product for such a high price

My daughter bought me a pair of my favorite Morning slippers from Woolworths about 5 weeks ago. I've always considered their clothing to be of excellent quality, as the prices are usually quite steep. This I don't mind, as I know that the quality of their products are usually with it. However, I was extremely disappointed with the quality (if it can even be called that). After only wearing the slippers for 2 weeks, I washed them. That very same evening, I noticed that the insides were extremely thin(not as thick and fluffy as its always been). I'm a diabetes patient. So good, strong and comfortable shoes are an absolute must for me. I thought that Woolies would not be a problem in this regard. I'm highly disappointed with this store. I don't even feel like exchanging the slippers, which feels as if there's thorns underneath my feet. At most... I'll be given a another pair, But because my disappointment is on a level where I wouldn't been want another pair of Woolworths slippers. It is truly disappointing paying R180 for such a horrible experience.