Horrible return service

I am utterly dissapointed in the return service from Loot, we ordered a Milex vacuum which stopped working after a while and a return was requested on 2 July 2019, 8 July 2019 I received an email to find out if the return was collected which it was not - no one bothered to let us know that a courier company was coming to receive the item - issue number 1

Then it was eventually collected and I had to make numerous follow up as completely no feedback was received - none- we received the fixed item back on 30 July 2019 - only to discover that there is no power cable in the box

So again I emailed and phoned 31 July 2019 - requesting for a manager to call me back - surprise surprise no phone call - what is left for me to do? What lengths do I have to go to to get someone to assist?