I get calls everyday, and they hang up straight away .
Why are they doing this.....does this not cost them?

I also get several calls. I am going to hurt these people.

Numerous calls since 7 Sep 12 with no one on end of call when picking up. Probably computer initiated. Caller ID shows this basic format 08842398XX. Once home phone rings 4 times it stops and it is immediately followed by my mobile ringing in the format 02841585XX also hanging up after 4 rings. These two numbers have to be linked.

I have been receiving a call from this number daily for the last 2 months - the first time I answered, no one replied.  Now I ignore it and it only rings twice and hangs up....very annoying.......

Numerous calls with no one on end of call when picking up. There is also a group of numbers doing the same thing starting with 02 8415 85xx