NV Waterproofing & Foundation Repair

In June 2017 I began communication with NV Waterproofing to come up with a solution to a small leak in my basement. When Mike first visited he proposed excavating my front yard and developed a contract that stated 50 square foot excavation that would cost $2500. This seemed reasonable at the time because our conversation made it seem like he would be exposing a 50 square foot stretch of the wall which would be a large amount of work. This is not what was done. A small hole was dug against the foundation taking his small team approximately 3 hours to complete. I wasn't at home when the work was done. I had already paid $1,000 and assumed that since the work they performed was considerably less than the work I had been led to believe they would be performing that they weren't going to ask for the additional $1,500.
The proposal Mike came up with after digging the hole involved waterproofing one wall of the basement for $23,379. This seems outrageously high especially considering other companies I had evaluate the leak estimated $7,000-$8000, although to be fair to NV Waterproofing, those companies were only offering a 5 year warranty while NV Waterproofing were offering a 20 year warranty. Because I don’t believe $23,379 is reasonable to waterproof one wall of my basement I am not proceeding with NV Waterproofing’s plan. So I have now paid $2500 to have a small hole dug in my front yard. Although this may just be a matter of extremely poor communication between Mike and I, it definitely feels like a bait and switch scam. The work that was done was not what I was led to believe would be done and the proposed plan is not reasonable. In our initial discussion Mike stated worst case scenario would cost me $20,000. Not $23,379 plus having to hire other companies to move HVAC systems and additional cost of NV Waterproofing likely destroying my deck in the process of doing the work.
I expressed my concerns to NV Waterproofing and they offered a $150 discount. I don't find this acceptable.