AF-360FGZ woes

I'm fed up. Bought a second-hand (apparently "demonstrator") AF-360FGZ from SRS on May 19. It arrived in double-quick time but the control wheel to adjust settings didn't work most of the time, whether I advanced it one "click" at a time or turned it quickly. SRS told me to return it and swiftly sent it to Pentax for repair. It arrived back some weeks later -- and the problem was as bad as ever. I then contacted Pentax/Johnsons Photopia directly, sent it back for another attempt at repair and I picked it up from the courier today. Guess what. The b****y wheel still doesn't do what it should do nine times out of 10. Has anyone else had a control wheel problem on this flash? Don't the Johnsons Photopia technicians check equipment after "repairing" it. Or am I doing something wrong, ie selecting the setting I want to change with the "S" button and turning the damned wheel when the setting is blinking? There. That's off my chest now. Thanks for listening.

Al no-flash

EDIT NEXT MORNING: Sorry guys ... I bought it on March 19, not May 19. If it really had been last month. I wouldn't be half as annoyed. Thanks for your comments.

I have found that wheel fiddly and awkward but it usually (always??) works. Sometimes it might take me an attempt or two to get it to do what I want but I have always put that down to my lack of manual dexterity!

no probs with my samsung version of the 360 as of yet.

The control wheel on mine is very stiff (although that's a good thing as it prevents it being accidently knocked) but I've never had a problem with no response whatsoever - sounds like yours is jinxed.