What hardware failure are they for?

Do you have any correspondence from CEX.IO to back this up?

The hashrate dropped to zero for hours.
I heard it was due to hardware i don't know for sure.
You can read it all on the support forum, about the failure.

As for correspondence, i received an email from the support team with an apology and voucher codes applied to me because I submitted a support tixket.

I run 1.5 th/s, so i suffered a huge loss. Around 15 blocks were mined, they didn't compensate for.

I sent you a PM Please check! I wish to buy it.

Yes sir i did because i was not compensated on my account, which i heard some user were.

i try if is scam or not
i has payed little for only 1 ghs (0,014)
i has received code but when i insert in cex i see
Redeem CEX.IO voucher code

Invalid voucher code!

i am waiting for correct voucher or refuse my money