Price increase after moving house

Hi, my initial contract with Virgin Media began in August 2022 for a period of 18 months at total monthly cost of £21 for M100 Fibre broadband, to go up to £44 at month 19. 

I moved house in July 2023 and a new contract began on this date for £28 with M125 broadband (I did not ask for this I just asked to move my broadband), minimum period 18 months. It also states there is a £20 and £3 discount for 18 months - but in the smaller print it seems to be sticking with the old contracts beginning date of July 2022) - says that this discount only goes up to February 2024. and as of Feb 2024, my new bill is now £55 per month. I phoned Virgin to explain this and cancel my bill, they advised I would face a £350 early cancellation bill and reduced my bill by £6.

So it seems like the discounted period of 18 months for my new contract has been cut to a period of only 6 months, as this discount period for the new contract was mistakenly dated back to my old contract Any chance of a refund here - thanks