My insurance State Farm covered 100% minus deductible as comprehensive since a rock hit it. The quote from Tesla on the roof is about $1800 installed. The bigger problem right now is stock of the part, I have been waiting 5 weeks so far.
What they told you may be because of how you described what happened. If it was due to debris from the road vs just part defect? I would inspect the outside and talk to your insurance again.
OP what insurance do you have?