Bad service for change of address

I am very UNIMPRESSED with Home-connect. I moved address and you would think it would be easy for them to just do a change of address. I have been without wifi for a month, no one at home connect could help fix the issue. Honestly no one at home connect even knew what the issue was, I was told 5 different issues by different people. Eventually I just cancelled with them. They told me they want to come fetch the router. I told them the date they can come for collection, they don't come that day for collection, they end up phoning me at work the next week saying they at the old address I must give them the router. I told them I didn't know they were coming, and I'm at work so I can't help them. I told them to arrange a proper collection time with me and they can have the router. I don't hear back from them. I now get an email saying they are going to debit me for the router. I don't want the router, they must please take it, but they ignore my emails about collection. Once I cancelled they also said the reason for cancellation was that "I was not prepared to wait". No I waited a month and needed wifi for us to work from home, and no one could fix the issue, so the reason for cancellation was incompetence from their side according to what they told me.