Not sure I fully understand the detail as written but at this stage, perhaps you might be a bit cautious before jumping to legal action.
Possibly, your next stage could be to email the Air Transport Users Council
The UK's Consumer Watchdog for the Aviation Industry | AUC Home with a formal complaint and at the same time, contact your local Citizen's Advice Bureau to test the strength of your case should the AUC not be able to assist.
At least that way you have a couple of organisations to quote when you rewrite to Globespan should the decision be to claim for goods or services not supplied.