Recognition of credit points and transfer between unis and fee scales

So if the University recognises credit points gained at another University and is allowed to transfer in from a part time M Litt to a part time MSc. Why do they then charge fees as though it’s a complete new start MSc rather than one year completed elsewhere and fees for only the remaining year of a two year part time course? Seems pretty awful they can do this and very unfair. Ie I believe they should only charge for the one year to complete and not for the year already paid and completed at another University.