People say to select emergency codes on a busy frequency if you need help, I can see both pro's and cons of this. Yes, you will get our attention and we will deal with the situation, but remember that we will also get a shock on seeing the flashing squalk which may put us off our flow and distract us from far more inportant tasks. I would say its best not to call Solent off your own initiative as the Swanwick controller may then just try and call you and waste RTF time when you have already gone, or Solent do some active controlling that Swanwick weren't expecting.
If the time yesterday you experienced this was between 8 and 8:30am local time then just sitting there waiting to be called/get a call in continuing your heading was the best way to cope with the situation. It was a nasty little session that I was glad to be out of and just watching from aside!