The catalogue companies really are a burden on the criminal justice system because of their questionable security checks and basically get a free publicly funded debt collection agency from the police and courts.
This is a very common police tactic who use these methods for a few reasons. A crime report for a recordable offence has been created on the local Home Office audited computer and the coppers so-called supervisors demand that the report is only finalised as 'Detected', particularly if the report names a suspect as these are easy targets for performance figures which the higher ranking 'police managers' need to make it look like they actually do some thing. It is much quicker and easier for copper if you admit the offence in full, time wise and paperwork wise. Once you have admitted the offence its not the coppers decision whether your cautioned or charged anyway. The quality of evidence and conduct of the copper is safer for you in the presence of a solicitor who is there to protect and advance your rights and interest. This makes it slightly more work for the officer so they tell you about long spells in cells and so on. The truth is, a solicitor normally has a far better chance of negotiating a caution rather than a charge in any case.
Unfortunately, although I believe most front line coppers have good intentions, they do get conditioned and hounded for detections.