Not willing to help with order after one minute of placing it

I placed an order and accidently took two of the same products instead of two different products of the same make and immediately realized my mistake. I contacted them and they told me it cannot be changed, that is after asking for help immediately. I now have to wait for it to arrive then contact them to return it and then place another order, how frustrating. Other companies would assisted me immediately and helped but not them. I'm totally disappointed in their lack of assistance.