Dissatisfaction with Travel in Pride

I am experiencing very bad service from this company. I paid for a premium membership in October 2023. I have not used any of the vouchers. However I had a small lunch and submitted my voucher for this amount. To date I have not received a refund. I have sent several emails without any success. Its as if they have "gone off the air". I intend to take further action to recover the amount that I paid for my membership. Does anyone have any advice for me. Thank you. Regards