Really poor carpet installation - can I fix this myself?

[Ellsa100]

I had a terrible carpet installation a year ago or so. Horrendous tradesman. It is a wool loop carpet

I have the following issues
1. the carpet is bumpy in places - see pics 1 & 2
2. I don't have threshold bars between rooms (as thought this would look better and what the carpet guy suggested. Where there are joins there is a bump and it looks bad in certain light - see pic 3
3. There is a slight dip in the width of the carpet which you can feel with your feet, although you can't see it in the photo - see pic 4

I've never done anything DIY with carpets. Is this something I could fix myself?

Could I get any carpet fitter in to deal with these?

Thanks

 

[HERTS P&D]

Did they replace the underlay when the carpet was laid?

Andy

 

[Ellsa100]

yes, should have been new underlay throughout. It almost feels like there is a gap in the underlay between two sections?

 

[foxhole]

Were the floor boards boarded out first ? Looks like you can see boards .

 

[Ellsa100]

The floor is screeded.

 

[HERTS P&D]

I would suggest that a new better quality underlay is fitted and the carpet refitted.

Andy