Yes, unsolicited text messages can be reported to the ICSTIS, either online,
http://www.icstis.org/icstis2002/default.asp?node= 34
Telephone:
0800 500 212 (free call).
Fax: 020 7940 7456
Write:
ICSTIS
FREEPOST
WC 5468
London SE1 2BR
They will take the matter up with the service provider and could have them fined and/or have the service barred if they are in breach of the ICSTIS code of practice.