> this type of conflict can only be adjudicated by courts, which low-income people don't have the time and money for

Massachusetts has a strong consumer arm at its AGO [1] and consumer regulator [2].

The problem is less one of cost of litigation than education about available options. (And the time to pursue them.)

[1] https://www.mass.gov/how-to/file-a-consumer-complaint

[2] https://www.mass.gov/orgs/office-of-consumer-affairs-and-bus...