Voucher download issue

HI, I am new to wordpress and this forum too so don’t know how to use it. Any way coming to Topic- I found Voucher Press Plugin very useful But Issue is-
1- I enabled the option ” required email register to download the voucher” but when visitor give registers, goes to his email and clicks the download Link- it says “sorry can’t be downloaded” ( using mobile ). again if visitors click same link from email, it says- you have already downloaded voucher where as visitors were unable to download it.

2- If i have Disabled option “Required email register to download the voucher” than visitors just click voucher & can download it from any device but if downloaded 1 voucher, it shows 3 vouchers downloaded. If i have assigned voucher to a post which can be downloaded 6 number of times than just after 2 downloads it says voucher over and in download history it shows 6 vouchers downloaded.

3- I request Voucher Press plugins developers to have a contact form atleast in their website. while trying to contact using Voucher Press website, it says login to contact us but there is no Login or register option in the website.

Please help me solving this issue.