Is $5,500 to replace septic pump and install new alarm a fair price?

I'm looking for some advice on how to handle this situation: I had a company doing some work on the outside of my house while I was out of town for work. While I was away, I get an alarm that there was water under my sink. Contractor checked it out and said the water wasn't going down. I'm out of town for the next 4 days. I call a full service plumbing company who schedules a visit. Their truck breaks down, they suggest to pump my septic tank in the meantime. Two days later, they finally get out and say that my septic pump is dead and needed to be replaced and a new alarm installed. I agreed to the bare minimum because they were suggesting $8500 in work. I get home, after dropping $5500, and find that the contractors working on my house had tripped an outside circuit and thats what caused the septic pump to turn off. $5500 in work because they didn't check that the circuit was actually on and/or took advantage of me being out of town. What should I do? Is this a claim?