B767 Captain reported Hazmat documents provided to the flight crew contained numerous weight and description errors. After making multiple attempts to correct the issue without resolution; the flight crew refused the Hazmat shipment and the flight departed safely.

Narrative

The Dangerous Goods form showed what I considered a large amount of Dangerous Goods. It was a little over 4;500 pounds of drill code 9L substances in 3 shipments; and another shipment that had less than a pound of drill code 8L. Two shipments of the 9L substances were the exact same amount down to the hundredths of a pound. The large quantity and the appearance of a possible duplicate shipment caused both [the First Officer] and me to raise an eyebrow. I called the dispatcher who connected me to the Hazmat desk. I was told by a supervisor that these amounts were wrong and that the paperwork was wrong as well. But; [the supervisor] didn't know for certain what to do and suggested someone in operations would need to figure it out. This began a series of radio and phone calls that led nowhere. No one knew anything about the hazmat; no one wanted to figure it out; and no one really cared. I called the Chief Pilot and had to leave a voicemail. I talked again to the dispatcher and asked to escalate the need for help to the next level on his end; and maybe even to the ops director. At this same time I'm getting more erroneous information from ZZZ ops that was basically a wordy plea to try and get me to leave without a resolution. I finally decided to oblige this request as it seemed the only way we were going to depart. BUT; only after ALL the Dangerous Goods were removed from the airplane. ALL of it was removed. It took a pay loader 3 trips to get it all removed and when they were done the final weights message showed a 12;500 drop in TOW. Which makes me wonder: what did it really all weigh? I wasn't sure if this decision was the greatest one; I would rather had accurate data and confident coworkers assuring the accuracy; but I didn't have any of that. There was no one that knew anything accurate about this shipment that could verify anything. At that moment we got a call from the Chief Pilot. He said he had been working the problem for about a half hour; could not get a hold of anyone who knew a thing about the DG on our airplane; and was in complete agreement with our decision to take it all off the airplane. He remarked that he was shocked at this; I told him we were both quite shocked as well. We were about 2.5 hours late to [our destination].