Amended Wedding Contract that was not signed

[Guest]

Hi, Please help! My wedding is booked for august 30th* - I booked and signed a contract back in September last year. In the signed contract it states that if I cancel 6 - 3 months prior to the wedding then I lose the deposit - which is fine - however they have sent an amended contract (they added on their DJ) and this new contract states that if we cancel 3 months before the wedding we lose our deposit and have to pay an additional £1000.00 cancellation fee? I ideally want to cancel the venue as they have been so unhelpful in the current situation but I don't want to have to pay £1000.00 on top of the deposit already paid? Someone has advised I tell them I do not accept the new contract (they sent this in Feb) and quote the signed contract but they have said this may be a grey area in the law as I did not reject the amended contract when they sent it. We didn't ever sign a new contract! However, it also says this in the contract*In the unfortunate event that the client needs to cancel the booking the Client shall be required to forfeit any deposit already paid and
to make such further payments as is required to amount in total to the following percentages of the anticipated cost payable as specified
in the Booking Form as amended by any later correspondence. Thank you for your help in advance.*