Virgin failing to process my refund

So I left Virgin Media back in May 2024,  I had a router to return and a WiFi pod, I had a couple emails and texts over the coming weeks about someone from Virgin passing by and they would collect the equipment. No one ever turned up to collect it. I had no more contact attempts from VM so the equipment just sat under the stairs. 

Come January this year I was remortgaging my house when the solicitors mentioned I had arrears on my credit file, turns out it's from VM saying I owed £75 since September 2024. They never tried to contact me or attempted to take this money from my card they had on file. 

So I rang VM told them my issue and they said if I paid the £75 now (to stop the delay on my mortgage) and then returned the equipment I would then get the £75 refunded.

This was back In January after multiple live chats I get told the same everytime that they will pass it over to a manager to process the refund.

And every time I talk to them its like they have no record of the multiple attempts I have made to get this sorted

Thanks,

Danny