Yes, he's right that they do honor the voucher.
You do have the $15 voucher which was rewarded through your purchase today and sits on your account for the next 6 months. The program works as follows: every $150 you spend in the store, it triggers a $15 credit for a future purchases. The credit expires after 6 months. I hope this makes sense and please let us know if you have any other questions.
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