Extremely unhappy customer. Wanted a plumbing job ...

Extremely unhappy customer. Wanted a plumbing job completed. Tradie on airtasker said he was qualified and he did an absolutely horrible job. It ended up costing me double to get the job redone. Who on airtasker checks that these tradies are qualified? Lucky for us no major issue happened with leaking gas. Will never use airtasker again.