Flexible travel means (according to the website): “Flexible travel: If you're travelling with a Eurail Global Pass, you can change things up at a moment's notice and take a different route if you like. Maybe you know you want to travel through Europe, but you don't know where yet or you want to be able to choose as you go. The Interrail Global Pass has you covered.”

“Flexible travel” doesn’t mean that you may choose your travel days the way you wanted to do it. So I think you just did buy the wrong pass. 

If it’s a wrong pass you get that you didn’t buy has to be verified with the price you paid and your exact order confirmation. At least it is possible. But this type of pass is clearly named “15 days within two months”, not just “flexible”.

Yeah I get you but I bought the 15 travel days in 2 months pass, so I'm not really sure what else I had to look for to clarify it for me?

How much did you pay for which class?

What does it say exactly in your confirmation email?

I bought it about three months ago, and paid €350, the pass was on a special. On the confirmation email it says 15 days

You forgot to write for which class but “15 days” is that what you got. So I still think you did buy a wrong pass, not that it’s a wrong delivery. The other one has to be named “15 days within two months”.

Is it a youth pass or an adult pass? 

Youth pass in 2nd class, sorry forgot to add that part

The price for a continuous pass 15 days for a youth in 2nd class is 332 EUR and for a 15 days in 2 months the price is 370 EUR. As you paid 350 it can't be a continuous pass.

It seems as if there is something strange with your pass.

You must contact Customer Support. Use the form in the link below. Give as much details as possible and indicate that you are currently travelling. 

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