Tour time was changed and didn't receive notice from Viator or vendor, Hang Loose, so my grandson and his girlfriend missed the tour. Was scheduled the night one day prior to them leaving the Big Island so was unable to reschedule. Now we are going through the refund hassle with no solution to-date. Haven't been able to reach Hang Loose by phone to deal with them directly and although Viator has contacted them feel like we are getting the run around. Hang Loose responded that they were there on time and called us to see where we where but we received ABSOLUTELY NO PHONE CALL. As Senior's on a fitted budget who were treating their grandson as part of a high school graduation present this is frustrating and costly...