Frustrated Client-Returns

I requested a return on the 4th of August. Dropped the item of on the 11th of August. Realized I forgot to include an accessory and contacted the call centre immediately on the 11th. I asked if I can drop it of at the collection point. They advised no worries they will send the courier during the course of the day. No one came. Called again the next day same explanation and being told it is being escalated. Still no one. Called every day until Friday to be told the same thing continously. I then received a mail on Saturday advising there was a fail with the courier on their end and they apologize and if I can drop it of at the collection point I should. I then dropped it of on Monday the 17th which was another damn hassle as they didn't wanna accept it because apparently I was supposed to wait for the courier. Waited there for almost 45 minutes until they called the call centre clarified their faults! And then took the remote. Now it's been 2 further days and the status is still "awaiting missing accessories"! I am waiting for my damn refund and it was not a small amount it was 1800 some change! This entire delay was your fault and even when I drop the item to you both times you still damn delay yet when payment is done u take the money immediately! I have emailed every single day and now I'm not even getting any feedback. I need this escalated asap