Anyone else read the actual books?

I've been enjoying MAYO on BBC AMERICA. It's light-hearted and quirky, and the stories have been interesting enough to keep me watching. In fact, I was so interested that I went to the library and checked out A SUNSET TOUCH by Marjorie Eccles, which was the basis of one of the episodes (house fire, two children missing, etc.).

The book is OK, but what struck me was how the Beeb once again has seemingly taken the shell of someone's book series and spun it out in a completely different way. The most egregious of these was HAMISH MACBETH, which has virtually nothing to do with the books on which it is supposedly based. MAYO is another example. None of Mayo's TV quirks are in the book; many of the characters don't match up; and most importantly, the plot is completely changed. I mean COMPLETELY. The whole basis for the plot, plus the supporting characters, are different. (On TV, you might remember this one as being about the proprietor of a hair salon; in the book, it's about a stolen painting and the dark secret of a vicar's wife.)

Marjorie Eccles is either fuming somewhere, or received enough hush money to sit back and let the Beeb's writers mutilate her work. If the Beeb likes a book series well enough to film it, why don't they use the author's work?