Parkdean Resorts complaint: Not adhering to their own T’s and C’s

Booked a holiday online and paid in good faith
Son then had to self isolate and then got covid – I sent all the proof needed to cancel holiday.
They sent me a voucher
I then re booked a holiday using voucher and a further online payment as it cost more than the voucher and I also paid extra for the travel insurance
I was then made redundant and sent evidence of this to them to cancel my holiday .
I was refused a refund despite me taking out insurance and was told I could only have a voucher
In their t’s and c’s it states if you have taken out insurance and paid with anything other than a debit card ( mine was paid with a voucher and debit card) then they will refund the monies via a bank transfer – I called and advised them I was expecting a refund and told that the system is wrong and shouldn’t of allowed me to take out insurance as it didn’t cover me for anything – I am now making a formal complaint