I travel a lot due to my work and this incident occurred to me for the first time. On Jan 2016 I went to Canada for four months, during my stay in Canada I was charged excessively every month. The only reason to have my phone with me was for emergency contacts. In those four months I have used my phone dozen of times to get in touch with my family but the bills came out excessively high. Bill from March - April was the worst € 134 , where as my monthly bill is € 20. So I Investigated my bill and I found out those additional charges were from outgoing calls and incoming calls from my own phone number . I contacted O2 Regarding the issue and I was told it was due to overseas voicemail service which did not made any sense to me cause I did not activated it. Suspicious thing is I have not made that many calls and I have not received that many voice messages and all I can see is outgoing (AB 004917x33xxxx3018) and incoming (AN 017xxxxx3018), which is my number repeating over and over again throughout my bill. I am being charged excessively for the service that I have not even used so can I get a refund. If O2 is not going to refund me could you sent me the details of the phone numbers of who tried to call me and the phone numbers of whom I called.