Realy after sales service in Hertz Gaberone

This is a compaint against Hertz Car Rental Gaberone airpot . I have retuned my vechile on the 17 th April and was told there is a valet fee as there were trace of smoke in the car. I agreed and a month later they are still holding my depost .This is the second time this branch did it to me . I have had commucations with Mr Tjezuva in Gaberone . I was told this will be sorted out in 3 days Yesterday the 18 th FNB informs me that the money was bank and not relased . Please can someone with authority investigate thsi matter My refernece is 85033801