Just to update with the end results of the website Feedback process.

Initially, the London Sales Office advised calling back immediately after I had generated a Feedback reference, but this was incorrect, you have to wait a minimum of 7 days before attempting to follow up on your submission.

Due to working shifts I was unable to actually call on 7th, 8th or 9th days after submitting Feedback, then received a call from the TK Customer Service team, in Turkey, on the 10th day, just as I was having my morning coffee, before phoning them.

Although they weren't able to say why my booing had been downgraded, they were able to inform me that they had cancelled the original booking and issued a fresh ticket, in the correct, J, class.

Apologies and thanks were issued and now all I've got to do is decide whether to carry on with my airside hotel booking, to allow for all of 4 - 6 hours sleep, cancel it and try one of the sleep pods, or just spend the time between flights in the lounge, trying to doze on one of the sofas.