But The Guardian reported in 2014 that "EE, Vodafone and Three give police mobile call records at click of a mouse", and in 2015 that "UK police requests to access phone calls or emails are granted 93% of the time", with rejection rates varying wildly by county from as high as 28% to as low as 0.1%. So it doesn't seem to be as hard as you're making out, unless things have changed wildly in the last few years. May I ask your sources?
https://www.theguardian.com/world/2014/oct/10/automatic-poli...
https://www.theguardian.com/world/2015/jun/01/police-request...
