After booking Premium Economy I received automatically (also got charged) for Economy. I mean, they should tell you before paying that you don't have the Premium available anymore, not after when it`s too late. Especially in my case, when I had to book a ticket for a very important person in our company and the ticket was not refundable.
Besides this, at some point on the phone, I was told (differently from what I was told in a previous phone call) that I will receive a refund of around 400 and that made me opt for cancelling the whole flight. Instead, I was refunded only 121. Looks like all the customer service employees work for different airline companies.
I had to cancel and lose the whole amount of money in order to buy another ticket with the Premium Economy option.
Never again will I use Trip.com