Unipin vouchers are unreliable

I bought a Unipin Voucher on Thursday morning at 6:50, been trying to get the PIN number since then, get error code 100, Unknown meter number or I also get the prompt to say my token will be sent to me shortly but it does not work. Sent the serial number of the voucher to 43471 on Monday, there has been no feedback as yet. I am of the opinion UNIPIN is unreliable, ineffective and is not a sustainable option, rather monitor your usage and go to PnP before it runs out, much more reliable and effective, just have to monitor. My voucher serial number is ***. Thanks