IANAL, however in my opinion (depending on country/laws), the repair shop would be responsible for a poor repair job, as it was them who carried out the repair, not the insurance company. Of course, you would need to report it within a reasonable time period, depending on what is actually wrong with the repair.
The main factor you need to consider is who directly paid the repair shop for the repairs, as it is them who have the contract of sale with the repair shop for poor services provided. So, if the insurance company paid you and then you paid the repair shop for the repairs, then it is you who has the contract of sale with them. However, if the insurance company paid them directly, then it is them who actually have the contract of sale with the repair shop.