Really need help with our lawn!

Hi,
We levelled our lawn as best we could and laid turf down - loved the instant grass carpet, laid in June 2017, everyone said we were mad, got a sprinkler, lawn was brilliant and all super happy.
Fast forward to now, it's quite lumpy, and various small areas went patchy so we used some grass seed from a packet from I think BnQ (I know, rubbish eh) - the cheap seed has grown totally different grass, much faster growing, thicker, more clumpy, so... do we:

1. Dig out all the crappy new seed?
2. Look wherever we got the turf from and look for that seed or try to get more turf to match?
3. How do we level out the lumpy areas as we already levelled it pretty well (well we thought so)

Obviously you'll need a picture - Im not there until after dark tomorrow but will post after that - if anyone has any general ideas it would be hugely appreciated. Thank you!

 

Weedkill the bit you don't want. Then you can get turf, or buy some good seed. I've just reseeded our front lawn with low-maintenance seed from Grass Seed & Lawn Seeds - UK Supplier - GSS DIRECT LTD and it's sprouting really nicely after only 2 weeks. (Not an advert - I'm just really pleased with how it's gone, after pretty indifferent results from bog-standard garden centre lawn seed.)

For leveling out the lumps and bumps, top dressing is the answer. Get some topsoil (plus sand if you've got heavy soil) and kind of brush it across with the back of a spring-tine rake to fill in the hollows. Don't put on more than about half an inch depth at a time anywhere - you can cover the above-ground roots of the grass, but you don't want to cover the actual blades of grass. Do it a couple of times a year, and after 2 years it'll be flat as you like.