User Activity

I need to speak to someone about a refund due to me, I have received an email requesting my bank details, but am reluctant to provide this and haven't got an contact for this, and the email address it came from is a no reply address
I discovered in Feb that several items had been ordered from my account. NOT by me. Have rung O2 nearly every week and have been told that fraud would ring me back.. Guess what still no response. I was also informed that my phone would NOT be cut off...