Airline hasn't Honoured my Seating Reservation and has still not refunded me

It has been 3 weeks that has passed since my flight and I had paid for reserved seating during the online check in process. The airline took my money and did not honour my seat reservations. I have contacted the airline on numerous occasions over email and logged a query on their website. No one is assisting me with my refund to date. Terrible customer service experience - as I am still waiting for my refund - CAS-387999-C1C3V2. I will have to get my bank and lawyer involved if they end up not assisting.