Incredible Connection selling expired PS Plus vouchers

I did an online purchase for a 3 month PS Plus voucher in March 2020. I only received my purchase around the ending of April 2020 and starting of May 2020. I tried redeeming the voucher on the 8th of February 2021 and it said that it was invalid. I contacted Play Station and they told me the voucher expired on the 1st of April 2020 which was before I received the voucher