So it's mainly the condition that's a problem rather than it being naturally unruly? I always find pure oil is more heavy duty than any nice conditioners from the chemist. Just slap on a whole load of olive oil or almond oil or something, comb it through put it up in a shower cap and leave it for a couple of hours, then wash it all off and condition as normal. Try doing it every time you wash for a while and it should calm it down a bit.
If it's all gone a bit triangular you could try asking your hairdresser to do something clever with layers next time just to make it less blocky.
Keep on conditioning and let it grow out a bit and it should get better.
Oh, and I really like using a conditioning creme instead of serum on damp hair after washing and conditioning. I like the phyto 9 one but you can get cheaper things that do the trick too (there used to be one called Vitapointe which you could get in Boots and Superdrug). Comb it through wet hair, tie or plait back loosely and then leave it alone (ie. don't try to brush it too much because it will make it 1000% frizzier!).
Oh, and another thing, one hairdresser taught me a trick if you've got wavy/curly hair. While it's damp put some styling creme or something through it then twist little sections (twist so much that they start twisting back on themselves if you see what I mean) and then leave them to dry like that. It makes more defined waves/curls rather than frizz.
That's it, I've exhausted all of my good hair wisdom! And mine is still looking dreadful today so feel free to ignore my advice !
good luck.