...my question would be did you merely book online with them providing your e-mail as part of the booking/confirmation process or did u actively provide your e-mail and agree to receiving commercial mailings from them?
if the former only then they are breaking recent EU and even more recent UK legisaltion outlawing unsolicited commercial mailing of private e-mail addresses...have just had a similar arguement with another EU carrier who seemed to think they could just use my e-mail provided during an online booking to commercial mail me...
If so report them to their upstream provider and OFCOM.