Poor quality product

I am utterly disgusted at the level of service I am getting at superbalist.com after having used their services a lot of times. I bought Nike sneakers worth R3000 at supperbalist.com in Novermber. After a few times having worn these, I discovered they are deflated. This, to me is due to inferior quality of the product and not necessarily negligence on my part as there are no visible holes or damages. Now I am told that my return/refund is declined due to their 'policy'. The policy they refer to really does justify them giving me as a client a product of poor quality. I believe i should get value for my money and it is definitely not the case in this instance.