Re: AdWords voucher not reflected in account summary. Why?
Please understnad that we don't have the tools on a public forum to troubleshoot your coupon issue. I'd suggest you review this article that explain how to use the voucher. Also, please, bear in mind that the most common problem with a coupon is that the advertiser tries to apply the code in the wrong region. Promotional codes don't travel well. If you received one in a particular region or country, it might not work outside that region or country. Check the code's terms and conditions for country restrictions.
Hope this helps,