Viator review: City tour failed expectations!

We took a 6 hr tour of Cabo San Lucas/San Jose Del Cabo; on May 16,2026. Picked up at 7:50 am at our hotel.
The 12 person van was fine however the tour guide although bilingual had an accent which made it most difficult to understand. This was exacerbated by the fact that the sound system in the van was terrible. We maybe understood 5% of what was being said. We and others complained several times yet no correction was provided. We spent $240 for this tour and filed for a refund which was denied as they said the services was delivered as promised. What part of underdelivered do they not understand. Up ;till now I had been pretty happy with Viator but now I seriously question their service and lack of customer service.