READ THIS BEFORE CONSIDERING INTERRAIL- I completely regret buying my ticket.
Myself and my partner recently bought 2 discounted tickets for 7 days travel to use within a month. We were extremely chuffed with the discounted price and the idea of a cheaper way to travel for our summer holiday. We then used interrails app to plan our trip, it was only when we logged into our account that we realised that we would have to double our costs in order to get on our chosen trains. Some reservation fees were quoted as €120 for 2 people, from Barcelona to Marseille. Furthermore, being less than 8 days before we travel, interrails online reservation service wouldn't work.
After searching high and low for a customer service number, I spoke to someone who then managed to get my complaint email sent on to the appropriate people. I then waited 2 Days for a response, in which I was told that they would give me an "exceptional" pass exchange. (After looking at other comments here, it's clear it's not exceptional). In order to exchange my pass, I need to get to a train station, get it stamped, send it back (at my expense) and then purchase another ticket (at full price this time) and then they will give me a refund minus €15 exchange fee.
Needless to say, I extremely unhappy with this "resolution". Interrail is a company that exploits those who cannot afford it. They should be ashamed of themselves.
For those of you considering interrail, don't do it! Save your time and money, it's really not worth the stress. Interrail have ruined my summer, and left me completely out of pocket and without a holiday.