Another common approach nowadays is to use multi-exposure HDR. Cameras even have it built in these days if you don't wish to do the combinations yourself. Programs such as Photomatix will take the multiple exposures and do the combining for you. No true PP involved!

Photomatix and other HDR programs will also take a raw file and treat it as if it was a multi-exposure and offer a selection of processed images for you to select your preferred version (you may or may not wish to tweak these further.) Given the high dynamic range of Pentax sensors this can be a very successful method, especially for photographs where multi-exposure isn't an option (thinking a high speed sports event for instance.)

If you've had them for less than 14 days you can just return them under Consumer Contracts Regulations.

http://www.which.co.uk/consumer-rights/regulation/consumer-contracts-regulations

Have you seen this? :
https://www.youtube.com/watch?v=NGgRqqu4Bkw

I recently successfully cleaned the inside of the front element of a Tamron 28-200mm. Mind, I mislaid one of the tiny screws for a week after it bounced to goodness knows where but OK now as I eventually found it!

Were they new or second hand? Also how long have you had them now? If you've had them a fair time the seller may suggest that you have caused the scratches (even if you haven't.)

That seems to be a common problem with them so maybe worth a punt. Who needs a power zoom anyhow!?

PM sent.

They truly are terrific shots. Well done. Like the contortions in #4 !

Just to point out that you said you wanted it for your K-1, not a KM or K2! Anyhow good luck with your search, I'm sure one will turn up eventually.
Link to a 'For parts or not working' one on eBay in Germany if you wish to sort it out.
Also just spotted this one said to be in good order in Wales: link

Interesting patterns . I suppose it's appropriate hosting photos of flames on flikr!

Just don't put it in hers!