For the purchase of the voucher, they initially sent me an invoice but did not send the voucher.
I contacted support to address the issue and it took from 3/29 when I contacted them to 4/12 when the voucher was finally sent to me, so 2 weeks. I did receive the voucher but due to how long it took I ended up using the free CC voucher found online to take my test (which had additional issues including a letter from ISC2 claiming that I didn't have an account and couldn't use the voucher...).
I am not sure if this is relevant in the case of CISSP for you, but my voucher included a year of AMF included which also was not supplied. When the voucher was sent to me, the year of AMF was not supplied at that time either. I am still waiting for that to be sorted out and even received a 'bill' that I owe $50. Currently I have passed my certification exam but can't get my certificate because my account still lists me as a non-member. Just in case membership was included in your purchase, keep an eye on that too.
