On 8/12/13 I called a plumbing company (Co.-A) ,to fix a sewerage back-up. I had cleaned up the water as soon as it happened, which caused no damage. Maybe two gallons of water, mostly from the shower. They then sub-contracted it to another company(Co.-B), because they were to busy to come to my house. Co. A was referred to me through Web site "TrustDale.com". Which offers satisfaction Guarantees. Co. B misdiagnosed the problem and believed to have fixed to the clogged sewer line. Five days later the same issue occurred with raw sewage coming up from the washing machine drain. Co b came back out and discovered that the actual problem was the main line outside the house was damaged from tree roots. This in turn was repaired at an additional cost. I have incurred @ $3,000+ in damages. Co A says they are not responsible because Co b did the actual work. Co B says they fixed the problem the first time and did not know about the root damaged line and it is just one of those unforeseeable instances . Is Company A or Company B responsible to pay for damages? Can I post this info on web sites?