Cargo Motors M2 City Mercedes Benz

So I recently took in my vehicle to Cargo Motors M2 City MB for the replacement of the thermostat. This repair was covered by Bidvest Warranty which I took after my factory warranty expired. Bidvest insurance is a reputable company and I never thought this will be a problem for Cargo motors but little did I know that after authorization for repairs, you cant collect your car until payment from Bidvest Warranty has cleared. I have used aftermarket warranties with other car manufacturers and never experienced such awful service.