Damage in a vehicle whilst on repairs

I was referred to Dals in Claremont by my insurer to fix a dent in my vehicle Mercedes Benz C200 (CA916217). I left the vehicle with them on the 29th March 2016 with no any other faults. I was called to collect the vehicle on the 01 April because I was out of town I went to collect it on Monday the 4th April. On collecting the vehicle I discovered that the dash board was dead. I brought this to their attention I was told to take it to the dealer as they worked on the dent which was on the rear left. I left the vehicle because when I brought it every this was working.. I was called 20min later that the vehlicle is sorted out, a plug from a cluster was out. I returned on Tuesday the 05th to collect and I discovered that the problem is still there and I left the vehicle. I brought this to my insurer (miway) I spoke to Chris Du Plessis who requested that the vehicle be sent for Diagnostic test . I was called on Monday the 11th to collect the vehicle and I must pay R2151.75.. I paid for the damaged that happened whilst the vehicle was in their workshop.