Bad service

Hi I’m not happy at all with how this company operates they not taking any customer’s queries serious!! I’m buying and selling cars privately so I have been buying cars every week through their online auction which I had a bad experience of delay to get my vehicle car registration documents on time according to their policy, I always had to wait more than 3 weeks before I could receive my documents. The worst experience that made me upset is getting my deposit refund back ,it took me about two weeks calling and asking help from their customer care centre to assist with my refund and still today my refund has not been processed.