This album exists in a bunch of different vinyl pressings, and has been issued on CD - I'm sure a non-'wowy' digitization of the album exists somewhere online. You should ask for your money back from 7digital, that's disappointing.
I did a quick google search, and there are a few tools that can de-wow' a recording, but I couldn't find a free option.
I haven't tried either myself, but "Capstan" by Celemony (the guys who made Melodyne) and RX Izotope both seem to have such functionality.
Good luck!