Speed court summons

I recived a court summons for not replying to a speeding ticket that had come for me!

At the time I was living in a flat with 6 other flats so had a shared mail box!

I was having trouble with mail going missing, I have Proof capital one as I had 2 cards sent and in the end we changed address and had the card sent to my parents house and a NatWest bank card I asked to be sent to my partners and I have texts sent to a house mate asking him about it

Anyway I recived the court summons and send it’s back and plead not guilty to the charge of not responding and guilty to the charge of speeding

I asked for my court date a wait,

A few weeks after I recived a fine of £220 and 3 points

I ring the court up and they apologise and adv will re add it into the system and will freeze the fine

Fast forward to today and I get another letter saying since I’ve not paid the fine they are now looking to take fether action with a warrant for my arrest or bailiffs

I then check my driving license and the 3 points have been added on

What should my next step be?