****** of my money

I tried to buy a car through Stucky Motors. They facilitated the finance with SA taxi. I paid a deposit and after going through to Sa taxi to finalise the deal. I was told there’s outstanding documents. Now because the finance did not go through. I am asking for my deposit I paid and I am told I signed the OTP therefore they cannot refund. There’s is no terms and conditions on the OTP And there’s is no breakdown as to how they will cover cost incurred. How do they thumb suck an amount. Their value is honest and integrity but they not leaving up to it. I don’t see how Mercedes Benz is dealing with them coz they are not honest at all and their terms and conditions are not in black and white.