Unfortunately O2 no longer have email support. I live in Thailand and being 7 hours ahead I always make sure I contact them by Tugo over wifi at 3.30 in the afternoon here. That and using snail mail are your only real choices and I certainly wouldn't trust live chat to close an account down correctly.
If you get to Rayong or Pattaya let me know and i'll let you buy me a beer/Sang Som
Enjoy your adventures
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