Refundable Deposit not paid Back

We hired their hay bales for a function in Jan'15 and their T&C's demanded one pays a refundable deposit to ensure non-breakage. They were dropped off on Saturday and collected on Sunday by Keith, without any damages. I requested to have the refundable deposit paid back into my account, provided them with my banking details and thanked them for their services. I then had to follow up via emails and ask when the monies are being paid and am being ignored point blank. To date no contact has been made, and neither has my deposit been paid back. This is not business ethics! If anyone wants to make use of their services, demand that they bring along the refundable deposit in cash upon collection, if not keep the hay bales!