Unfortunately there is nothing you can do about the delivery time. 

As @rvdborgt answered in your previous post.

 Trenitalia still sell paper Interrail passes:

https://www.trenitalia.com/it/offerte_e_servizi/faq-interrail.html

I bought my pass in the sale for the 50th anniversary. It said in the sale, that the pass can be bought now and used whatever date for the time purchased. But there is a timestamp on the pass, but it starts in June and I will only start using it the beginning of August. So what can I do, do I just write down the date it’s valid or can I change to a mobile pass? 
I only realized now, that there was a date on it and I need to use the pass next monday. 
Please help with solving this. 
Thank you, Nina

When you bought the paper pass during the sale you had to choose the start date of the validity. That is nothing that can be changed.  The passes from the sale can't be exchanged.

You have to use the pass during the time that is written on the pass. 

Did you buy the 1, 2 or 3 month pass?

Yes, I got the pass in the sale. It said everywhere that you can start whenever you like, so I did not know that that was not so for the paper pass. 
I chose the 3 month pass. So I wanted to start it next week and use it till the end of October. But unfortunately it startet running already in june. 
So what can I do now to be able to use it until october? I have not used the pass yet, it’s still blank. 

You can't do anything apart from travelling as much as you can while your pass is valid. It is only with the mobile pass that you can choose the start date of the validity within 11 months of purchase. With the Interrail paper pass you decide the start day of the validity when you buy the pass.

You can always make a complaint to Interrail saying that you feel cheated. 

https://eurail.zendesk.com/hc/en-001/requests/new