This 0870, 0844 thing annoys me especially when you are talking to someone on the phone who dishes out a non geographic phone number for another department or to call them back I always ask for the geographic phone number they usually bluster saying they don't have one, had this on one occasion and they where adamant they only had an 0870 number the thing with this call they had called me and CLI gave me the geographic number I asked them if they wanted to make a note of it for when they where asked again
If you have to dial a high rate 08XX number when you get through ask them to call you back