BABIES R US RETURN/EXCHANGE POLICY

I bought 2 NUK bottle teat from Babies R Us a few weeks back because my baby was turning 6 months and I needed to change her teat to the next stage. I mistakenly took the teat for thick liquids and not for the formula. I went to Babies R Us Pavilion and was told I need a receipt to exchange. I didn't keep the receipt. I also cannot remember the day I went to the store because I purchase from the store almost weekly. I find this so unfair because all I want to do is change the teat to the correct type of teat but I am being told I need a receipt or the date of purchase. I am really upset because I have no need for this teat and it will now cost me more to buy something that can be easily exchanged had I gone to any other store. I will have to change the store I shop in because of Babies R Us's policy.