Dear forum,
Have been lurking for a while, but this is my first post, so please accept my apologies if this is the wrong place to ask these questions.

I admit, I am a DIY person and not a qualified electrician.

My quandary.
I requested an inspection of my home electrical installation (house built in the 40's, but significantly altered since then, including the electrics) and some of the issues found were as follows.

Cabtyre extension leads fed from an internal plug supplying a booster-pump and grey-water installation. The cable was protected with a PVC pipe outside and secured to the wall and connected to a protected plug box 1m from the installation.

CoC was denied as cabtyre may not be used for a fixed installation. So this was an extension lead beyond the point of consumption and I replaced said cable with Twin + E (1,5 mm2). I am awaiting the delivery of 16A fused plugtops for this.

Original company refused to "sign-off" or re-inspect (I expected this), so approached company B.
Company B now refused to issue CoC as I used undersized Twin + E and wired into a plugtop. Inspector stated it should be cabtyre if wired from a plugtop.

I am now very confused and am seeking clarification on the use of cabtyre and twin + E when used as an extension lead for a fixed installation.

Thanks for a very informative forum