Non-Payment of Refund

When my contract started in 2019 July, they asked me to pay a deposit that will be returned until contract expires before they could offer me a contract. I paid the deposit and all my statements have been reflecting as "Deposit Retained until final account". The account ended and I have requested for my deposit back. I have been making follow-ups for weeks now and they are telling me I do not have credit due for refund. The Telkom service is bad to say the least. They are refusing to pay me my deposit back. To make matters worse they don't even give feedback, you have to call to get feedback and the consultants you are not responsible to resolve this, people who resolve them will never call you back to understand what's the problem. Useless.