Priceline complaint: cancelling my flight and wrong information

I cancelled my flight August 19, 2021 to Cancun, Mexico through Priceline due to COVID. I was told I had end of the year Dec 2021 to rebook my flight. When I called them in December they had told me to call Delta to book my flight because the credit is through them if I’m going to not use all my credit. When I called Delta they said I had a year from the date I purchase which I purchased in May 2021 so a year would be May 2022. I called 3722 to book a flight through Priceline and they said my credit was not used and now I can not redeem it because I had until end of Dec 2021. I tried calling Delta to resolve my issue and they can not locate the credit. I am getting the run around I am submitting a complaint on both Price line and Delta Airline because it is not my fault. I did everything I could to redeem this credit of $1,159. I wanted to spend it by taking my kids out to Disneyland with my credit that I was told I had.