purchased wrong tommee tippee teats

i purchased 2 boxes of tommee tippee bottle teats. when i got home, i realised the packaging has a diffrent colour from the 1 i buy and they did not have a hole like the 1s im using for my baby and the pricing was high. after a few days, i went back to DiSCHEM, SOUTHGATE MALL with my receipt to return them. i was told to talk to the lady supervisor. i told her i would like to exchange. She asked me to go take the 1s that i want so i can do the exchange. To my shock, when i returned to her with the standard teats, she told me she cant exchange for me as i have used the teats. i told her i had no reason to use them, the packging was diffrent and they were not opened. She told me she can see that it was used. i wonder how? cause this lady did not even bother to open and check them. she said i tried using them and when i saw they not suitable for my baby i returned them. LOL! i found this so disrespectful, when i being accused of something i did not do. she said i used 1 box. i then told her that i want a refund. she only refunded me 1 box. and im stuck with 1 box, believe me when i say it was never opened. im so angry wil never buy from this store ever again! so disrespectful!!