Claim was approved now it's been claim due to unseen damages that the assessor missed

On the 5th of August I was involved in an accident, the other car bumped my Car from the back. My car was towed to the panel beater where the assessor went and assessed the car and concluded that the car can be fixed with the damages that are costing R 69594.12 and they fixing it. I was advised to be in contact with panel beaters about the repair progress. I did a follow up on tuesday and I was told there were "unseen damages" that where found and the assessor was there yesterday again. Today I received a message from panel beater saying my claim to repair the car its been cancelled because the assessor is going to write it off and since I paid the 50% excess fee they will refund me

When I contact the insurance, they saying they haven't received any report from the assessor about this, as soon as they do they will be in contact with me.

I need clarity on how does all of this works. 1stly on how come did the assessor missed the "unseen damages" what made the damages to cost R 69594.12? How competent is he? A boot and bumper that cause so much? What about the lady who bumped my car, isn't she and her insurance iwyze supposed to be paying the cost of my damages since the panel beater claim that its uneconomical to repair it thus the write off. Can I get details of the assessor's report on what are they fixing

I am not happy with the service, I m on my 3rd week without a car and without any progress. This is straining for me because this car is my mode of transport to work.