0844 - It rang. I tried to pick it up but it stopped after two rings. The missed call log showed "Private no."
0845 - It rang again. Same thing happened.
0847 - It rang and I grabbed it on the first ring. Someone with an Asian accent answered. He responded every time I said something but his responses didn't make any sense - random snippets of English among some other language. After about 30 seconds I suspected I was talking to a bot and hung up. The received call log showed "[no number]"
0849 - It rang and I picked up. Total silence so I hung up after ten seconds. Call log showed a number beginning with 07984.
0851 - Silence again. Number began with 07908.
0854 - Silence again. Number began with 07939.
0854 - The Indian voice again. The responses weren't exactly the same as the first time but they were similar enough that I was convinced I was talking to a bot after about ten seconds and hung up. Call log showed "[no number]"
0855 - I didn't bother to answer it. It stopped after two rings showing a missed call from "[no number]"
It's now 0920 and it hasn't rung again. I would have guessed this was one of those scams to leave a missed call so you run up a bill calling them back, but it never showed a number on the calls where I didn't pick it up. And what was the point of the robot on two of the ones I answered? They called me so they were only running their own bill up by keeping me hanging on the line.