I'm fairly sure you have to read and sign something from JCQ and acknowledge the exam rules a few weeks before an examination.
Even if not, it is your responsibility to know the rules. You had been given the letter stating a short, supervised break.
And more, there will have been an A3 poster with a super size 'no mobile phones' clip art directly in front of you.
You were trying it on, and though the invigilator was clearly a retard, it is completely your own fault.
Finally, you failed GCSE modular Maths???