Not sure why they are squeeking, or how to stop then sqeeking. Any ideas please

One for Chris Gilly I feel

If the surfaces aren't worn down, there is a spray for brake surfaces but I don't recommend this.

Usually a bit of copper-grease on the back of the pads and along the moving edges sorts it out, if there are anti-squeel shims or springs, grease them likewise, very thin amount.

Make sure you don't get any grease on braking surfaces or in places likely to leech to them. Don't use a normal grease, its not high enough temperature rated.

Are they getting low? Pads often have a steal spring which touches the rotor when they wear down, and make the pads squeek to let you know they are getting low.

Pads can also squeek if the discs are getting low and there is a lip on their edge.

If there is plenty of meat on them, greasing them like DD said should fix it.

they have only been replaced last month

defo copper grease the backs however if a cheap brand of pads were used then he friction linings tend to be a poor quality and squeal anyhoo,

Also maybe worth changing discs too.

He used Mintex pads and discs. A decent brand??

Mine are doing the same too and I used mintex, I even took them off and applied copper grease. So im completely stumpted too.

Mintex are known to squeek a lot but they are one of the best pads available for performance.

Depends on the pad compound - the OEM replacements shouldnt be any harder than the OEM pads.

When putting some copper slip on the back of the pads / anti squeel shims, als give the caliper and carrier a good wire brushing where the pad sits, and also copper slip the tracks that the pads move in.

Obviously dont slap it on everywhere, but if it gets on the brakes its not a major issue as it will clear it off first time you brake

Yeah, wire brush the whole area. I've been done twice in the past by that metal 'low pad' screeching sound, I thought my wheel was about to come off, I had no idea what it was.
The pads squeak because they're not greased up, just cover them with copper grease

cover the back though NOT the bit that touches the disk!