First, let's make sure you've got a definite species ID of moles. The "maze of tunnels" part of your description makes me wonder whether you might have voles (or gophers) rather than moles. Could you please attach a picture or two of the network of burrows (and/or mounds that you're seeing over the area?
 Species ID is important as we think about how to make the area immediately surrounding your window wells "Not habitat" or unnavigable by the creature at work. Really for most of these, having a contractor dig deep (18-24") and laying rough gravel around each of the wells would likely stop the tunneling (regardless of species), but then you'd still have a drainage/runoff problem. It also seems that regardless of species ID, a conversation with a contractor about managing drainage/water flow on the property might be helpful. The tunnels sound like they could be part of, but possibly only part of a broader grading and drainage challenge on the property near the structure. 

Dr Sanchez, Thanks for the quick reply. I can’t get a good picture of the maze because I have already knocked down the mounds that would have marked it. I attached mound pictures from around the yard.

A little background - We do have drainage issues because of the position of our house on a hill that would be complicated to deal with externally because of existing landscape and hardscape. 10+ years ago, we dealt with rain getting into the basement by having an indoor waterproofing system installed. It consists of water impermeable sheeting up against the concrete on the inside wall that directs water into a French drain at the base of the wall that then empties into a sump pump. This has worked as expected during times of heavy rain. We had the waterproofing company out and they concluded that the drain and pump are working OK. They won’t do anything else unless we have rain water coming in. There is no obvious explanation as to how the water from the mole tunnels circumvents their system. If I can’t deal with the current problem externally, the next step will be to cut out some drywall and try deal with it internally.

I have already dug out dirt in the window well to a level a few inches below the mole tunnels. I am thinking about putting several inches of ¾-minus gravel in the bottom of the well and doing some sealing along the ends of the housing. Would there be any advantage of adding ¾ inch hardware cloth around the bottom? After doing something inside the well, I could dig around the outside and put ¾-minus gravel around the bottom of that trench.

I am hoping that just reducing the amount or rate of water reaching the problematic hole in the existing barriers will suffice.  

I am curious to know if it might be a vole or mole and how you decide.

Steve

The pictures are helpful, although I don't know what I'm seeing with the light dots on the first photo. You either have moles (insectivores) or gophers (herbivores). Voles don't make the mounds you're seeing. To identify which (gopher vs. mole) is making the mounds, you really need very fresh sign - The clue is whether the little slightly-sunken plug is right in the middle of the fresh mound (mole), or whether it's off to one side of a more "fan"-shaped mound (gopher). This Extension pub from Missouri has a nice illustration (Figure 4) that helps show that https://extension.missouri.edu/publications/g9440
That same publication (further down) has illustrations of trap designs used for moles, whereas this one https://icwdm.org/species/rodents/pocket-gophers/pocket-gopher-damage-prevention-and-control-methods/ illustrates trap designs and deployment for gophers. 
It seems like population reduction (and ongoing management) would be helpful in reducing how many burrows you have near the home. That still won't counteract the waterflow issues with the grade. I think gravel and/or hardware cloth near the wells would help reduce burrow-building right up to the wells, but water would flow through the gravel even more consistently than through a "pipe" built by an animal. I really think you need to consult with another contractor and perhaps gopher/or mole population reduction PLUS an outer perimeter of water drainage tools would be needed to supplement that which you've already employed.