I'd agree if it was the vehicle owner paying for the repair, otherwise it is generally it is not up to the insured to get independent quotes, the insurance company should appoint an assessor to assess the damage and make a recommendation to the company.
Whether the repairs go ahead or not would be their decision, which would be based on the cost to repair versus the insured value of the vehicle.
Any dispute should be resolved immediately.
In my experience, the car will be taken to the repair company by the insurance company, exactly where will depend on the clause in the policy, i.e. dealer garage or an approved insurance repair company, the insured may have a say in the preferred repairer, ultimately though it is entirely up to the insurance company as they are ones who will (should) be paying, the insured would forfeit any deductible if any and the repair should then proceed, some insurance companies do seem to have a bad reputation with the dealer garages in terms of payment and can be slow to give the go ahead to repair, however, after 8 months in the case of the OP, then something is badly wrong.