The prospect pack should explicitly state that the skills for the mining barge are temporary and not permanent. This is a blatant false advertising issue.
Hi, I can’t find a ‘Prospect Pack’ in the store; can you point me in the right direction? Thanks.
I cannot find the Prospect pack either, it’s not in the web store nor in the ingame NES for me.
Maybe it’s only visible for new players?
What I do see is the mining barge expert system in the Industrialist pack:
But there it explicitly states the mining skills are temporary for 7 days to try it out.
If that isn’t said in the other pack I agree, that sounds like false advertising.
A 2 second quick google search 
revealed this:
https://store.epicgames.com/en-US/p/eve-online--prospector-pack
Safe to assume OP is talking about this one.
Edit: It seems to only mention Skill Point token but does not explain what it is nor mention it provides temporary skills (assuming it is meant to refer to the Expert System, though can not be 100% sure about it but if this is what OP bought and it is indeed just an ES then he is right).
Maybe it is a good idea to bring this to @CCP_Swift’s attention. 
Edit2: Just for reference and archival purposes:
2 Likes
Token must be an epic games thing
Or maybe not:
Sounds like a character screen redeem item that grants a fixed amount of SPs.
Maybe this one:
Though this is just an assumption. However this one should grant permanent (unallocated) SPs so also assuming OP is not talking about this as what OP describes sounds like an Expert System instead.