How to deal with the constant bickering...

[Jesusgirl]

I have an 8 year old and a 3 year old and over the past 2-3 months, all they do is this very annoying bickering. It's really driving me up the walls. TO the extent I've told them to stop playing with each other- I know that's a bad option but I honestly feel like pulling my hair out when they start the 'yes you are' ' no I'm not' 'mum x said I'm this and that'

I've tried punishing them, taking away privileges, nothing seems to work.

Help please!

We have that. 5 and 3 and they are at it all the time and yes we separate them. There are also side-swipes , undercover pinches... I don't know what to do except over-praise and reward the little time they spend together without fighting.