Stripped Bolt

My Opel Astra GTC was taken in for a service at the Fish Hoek branch. I was called to say that the sump plug thread was stripped and it would be repaired at the cost to me, the client, at R625.00. This is the second bolt that has been stripped. The first was a wheel stud which occurred at the previous service but was repaired at Thorpe Delta's cost..<br> I was told that the reason this thread was stripped is because it is a very fine thread and of aluminium construction and \these things happen from time to time"..<br> I feel that due care and attention was not paid. Threads on bolts and nuts are in my opinion only stripped when either it is cross threaded or undue force is app****. Why should the customer pay for what is negligence on the part of the dealer?.<br> I have been a customer of Thorpe Delta for 15 years and will now not take my car there again as I feel that I have been very poorly treated.. R625.00 for the Dealer is not a lot of money when you are dealing with your good faith and reputation."