Movistar cellular phone review: not cancelling my line

I have a line with them for 2 years contract which ended on Oct 9th. I was leaving the Country, moving from Mexico to California, on Aug 14th, I prepaid the entire rest of the contract at full rate. After I had a confirmation that the line will be cancel on that Oct 9th automatically, I left the country I call on Oct 9with a peaceful mind. On Oct 9th, I was nervous about it...My six sense told me to call to confirm. I called to find out that the line was not cancel, but no problem, I was still on time since we were Oct 9th. I am was glad I called!

I was online with the cancellation department, and they were asking tones of question about why I am cancelling, and to proof of identity.
I did not have the right my mailing address, in my file, not sure why. But I gave them all my previous address and none of them were the correct one matching the one they had. ( I was always receiving my bill by email) They refused to cancelled my line! I got so upset that I hung up and called back to speak to someone else, because this agent did not want to do anything about it. But calling back the line was not picking up since it was now after 5pm! I call the following morning on Oct 10th, and they said it was too late I had to pay the month that had just started. I try to escalate the situation none of the executive were able to resolve my case. They open a special report with a folio number, and told me to call back the following morning. I called back on Oct 11th, to find out that this folio does not exist. I explained again the case to someone else, no solution were given except to pay the month (1900mxp), or to call back the following day to see if some one would respond to the folio number that I had because so far they were not seeing it. I call ed back the Monday Oct 13, still nobody had worked on the folio. Called again Oct 14th to speak to someone else, who told me after explaining again everything that she would cancel my line, without further question! Finally! I asked her to send me a written confirmation, which she never send as of now, 48hrs later, and the phone is still working... and I received the bill by email! I don't know what else to do. I am not living in Mexico Anymore, not going to return soon. I am no longer have bank account there, but I don't want my credit to be affected.