Fujigoko Enjoy Ticket

Hi,
It is written in your website that this ticket is valid for up to seven days. I don't understand what that means because it is also written that the pass is for 2 days.

Is it possible to make the return journey on the third day?

my plan is to take the bus from Tokyo to Fuji lakes area on Tuesday, travel there by bus on Tuesday and Wednesday and return to Tokyo on Thursday. Is it possible with this Fujigoko Enjoy Ticket?

Another question, where exactly in Shinjuku station I can buy this ticket?

Thanks,
Daniel

It is written in your website that this ticket is valid for up to seven days.

What website? I cannot find any statement in the direction that the ticket is valid for seven days. It is valid only for 2 days:
https://www.japan-guide.com/e/e6905.html
http://bus.fujikyu.co.jp/otoku/fujigoko-enjoy

Is it possible to make the return journey on the third day?

No. It is only valid on two consecutive calendar days (midnight to midnight).

Another question, where exactly in Shinjuku station I can buy this ticket?

At the ticket counter of the Busta Shinjuku bus terminal.