Being asked to pay despite having cancelled contract
I called up 1st March to cancel my contract and was advised it was fully cancelled and the last day will be 31st March and that my final bill will be less then £10 as I will only be using a few days worth of the broadband. I was also told that they will be sending a box to send the equipment back, but I am now being told to pay a £80 bill for the dates 27th March to 26th April.
I sent in a complaint and was told the account was not fully cancelled and only the phone line was cancelld (the phone was ported over early due to the number needing time to transfer), however I had contacted many times just to confirm the entire account will be cancelled over phone and via the live chat. I even have screenshots of them confirming the full service was fully cancelled. What are my options. I have tried calling and sending complaints but this seems to be going no where.
Thanks
Jason