Mills & Boon

Please beware buying books or ebooks from Mills & Boon, there are many other book sites around with great customer service.
I have purchased nearly 30 ebooks from this site and no problems so no need to contact them, however few days ago I purchased 3 books and 1 free book, i downloaded the ACSM file and I always open with my authorized adobe digital editions, however when i tried to do this it came up with an error saying already fulfilled by another user, the three purchased books wouldn't open but the free one was no problem, so i knew not an error with digital editions plus I only have one log in.
I emailed customer service and no reply, I emailed again the next day and they basically said sounds like a problem with the DRM and I must not have used correct authorization on my ADE (but they did not explain how 1 of the books was ok) and basically tough, £12 lost and no books and they will not reset the 3 non working ones on my shelf on their website!
I have sent another couple of emails since and no reply at all from them.
I would definitely recommend thinking twice about purchasing from this site, I have paid for books i can never read and they have kept my money.