Superbalist.com
Amazing Service and Care from Superbalist

I placed an order at Superbalist during their 20% off deal and forgot to use the promotional code to get my discount.
The next day I realised my mistake and emailed the support. They immediately refunded me the money so that I would get the discount.
I don't think any other company would do this. They would just point to the T's and C's and say "tough luck".
Their service is easy to contact and they go out of their way to fix errors, yours or theirs.