Ithuba is holding my security money while I'm no longer they client or retailer

I had a lotto machine at my shop, I was paying on time but had a challenges where I paid it two days late. I was called last month and informed that the machine is not making much profit and it will be de-installed, three days later was indeed de-installed. I submitted my banking details on the 2nd of this month till this date I didn't get my refund. I believe I'm not your client or retailer anymore, I don't see any use to hold my money for this long as I don't have any outstanding invoice. Since I had this lotto machine in 2019 and I paid the security money that year before the machine was installed. Is this fair that you kept my money that long without accumulating interest? As now I'm no longer your retailer I believe now my money will accumulate interest of 2.5% daily from the 2nd of this month till you pay me. I believe you invested my security money to make profit and fail to understand why when you pay me back it doesn't come with interest.