Parkdean Resorts complaint: Holiday lost

Hiya,
Not sure where to look, but basically we had a holiday booked for last May as a surprise for my mother’s 60th. I booked 2 caravans and had saved hard for this (I’m a loan parent, working 2 part time jobs, studying at university for 2 degrees.) when lockdown happened the holiday was cancelled and we recieved a voucher. I used the voucher in August, and rebooked 2 caravans, one completely paid for the other had an outstanding balance of £86. I had no emails to say the outstanding was due (26th Feb), and the only email I recieved was to say it was cancelled due to none payment. With covid, I had completely forgotten and from my understanding of boris announcement, only self catering cottages are open. The park isn’t fully open when we are due to go (7th May), and although services are maybe being moved outside, I can’t take a 3 and 7 year old outside in the cold constantly, no soft play etc open. and they’re refusing to give me any of my money back, and saving that I can not cancelled one caravan and put it towards the other as its 2 bookings, although I originally booked them together, voucher came back as one booking, and then I rebooked them together. Please please help with any advice, I’ve worked so hard to save for this, and it’s what my 7 and 3 year old daughter have been waiting for all this time.
Thanks
Aimee Nicholson
07944724204