Nursing bras excluded from return policy due to "hygiene" issue

I recently purchased a nursing bra from babies R us. There was no fitting room at the store so I was required to purchase the bra without trying it on. When I tried it on at home the bra was too small and the cut was uncomfortable.

I tired to return the bra at the Somerset West location but the manager told me that it could no be returned for hygiene reasons. He used the example of returning a bra at Edgars; however, you can return bras at any major retailer including Edgars. Furthermore, all retailers have fitting rooms for you to try them on before purchasing because every bra has a different fit. A bra is not a hygiene item.

I am extremely disappointed in babies R us' return policy. Can you please explain why they do not allow returns for bras? There is no fitting room fit customers to confirm the size and fit, the tag is still on, and I have the receipt.