I can't follow your question. Why should anyone hack into my customer database to send me unsolicited mail? Should 'you', in your post, read 'them'?
Anyway, the fine details are unimportant. 'Hacking' is illegal and so is sending unsolicited commercial emails (i.e. 'spamming').
The UK regulator, in respect of both hacking and spamming, is the Information Commissioner. That's where you need to direct your complaints, rather than to the police:
http://www.ico.gov.uk/complaints.aspx
Chris