spark plugs 2000 ranger 3 L V-6

On 7/28/14 I took truck in for new spark job. On screen and printed flyer a summer special discount of $25 on any service over $100. I stated that I didn't want new wires. I waited over 2 hrs while mechanic said engine was too hot to work on. They first called be to the shop because they said the wires were too old to save. Then they called me back to show me the broken plug with contact tip missing. They next showed be the same plug with more of it missing insisting that it had been broken already. They soaked the threads with penatrating oil over night. The next morning they broke off all the plug with wrench flats. Two more days later they drilled out and removed the plug with an easy-out. They said I would have to pay for the easy-out tool and 2 1/2 hours of extra shop labor. This seems excessive for drilling out one plug and backing it out with an easy-out. The final bill was $532.68 and they took away the $25 special and $10 off the 96.92 wire set. they had on the earlier estimate claiming it was to pay for the easy-out. Lee Curtis