should I sink more $ into this van or trade it and get away?

What is your question?

2003 chevy venture with 124,000 miles that had a water pump replaced and tuneup. Number one plug broke off in the head and the shop had to drop everything down drive train, etc to get it out. The fuel gauge was staying on 3/4 to full all the time, also. I got it back, it started overheating almost immediately. Was told that the mechanic forgot to fill both the radiator and reservoir. Took it back in, Radiator was flushed and bled, thermostat replaced, manifold gaskets new, new distribution block and burned wires replaced. Still goes into the red and shuts down engine after about five to ten minutes of driving. shop says the only thing they can figure is the block is cracked. I'm ready to give up! Any ideas?