Charge after termination

Due to unresolved VM network problems i used the one touch switch on 2nd April 2025 to move to a different provider with a switch date of 25 April 2025 which is exactly when my 18 month contract ends.

This was confirmed by Virgin Media, stating an "Early Disconnection Fee of £1.14".
My new connection was up and running on the 25th April and the VM box disconnected.

Have now got a bill of £57.20 "Your package covers the period 26 April - 25 May".
Why am i being charged after termination?  This bill looks like the start of a new 18-month contract and i certainly don't want that!!!  (previously i was paying £36.99/month) 

Tried to query this with Virgin Media repeatedly and found it impossible to get through - have now spent over 2 1/2 hours on the phone (0345 454 1111).
The call is placed on hold and eventually gets disconnected.  Still haven't managed to speak to a single human being!

Tried the online chat and after waiting ages, Myrna joined the chat and for security asked for the 11th letter of my 8-character password!
Finally Myrna said i should pay the £57.20, which will get credited back after 45 days - this sounds wrong to me and i still don't know what the bill is actually for.
I don't want to pay this and get locked into another 18-month contract.

Also tried to raise a complaint on the VM website which fails.  When i submit the complaint it returns a row of "*" characters as the reference:

"Your complaint reference : ****"
"We've not got any ongoing issues connected with your account, so there's nothing to see here."

And yes, i was logged in and tried this twice with the same result.

So where do i go from here?

 

[Mod - title edited for clarity]