Refund from crescent logistics

Hi, I need help with recovering my R200 000.00 that I deposited into crescent logistics as a deposit for the 3 34ton trucks that I had to lease. Crescent logistics now known as earthmove logistics are refusing to refund me . On the 25 April 2019 I deposited R200 000.00 as a deposit after they insisted a pay a deposit for then to hold my trucks. A week later I emailed them requesting a refund as I didnt have any use for the trucks. I was assisted but a young man called Kelvin his number is *** requesting my refund. He the. Advised that the refund requested has been forwarded to the legal department for review . After countless attempts to call the legal department I then spoke to a gentleman called Sam from the legal department . He assured me that the refund will be processed and I will only recieve my money 30day after statement date . The statement came on the 26th of may meaning I will get my money on the 28th June 2019 . On the 28th of June after being sent from pillar to post they send me a settlement undertaking letter for me to sign acknowledging that the refund is due but can only settle on a month to month base . I didnt sign that letter . Can you please help me get my money back from these crocks