Claim of Loss of Use

I am involved in an accident where I was knocked by a car from behind.
My car was sent to the workshop for repair and the total time taken was one month and one week.
It took so long was due to the adjuster report and the Chinese New Year holidays which fall in between.

Due to the transportation system in my area, I rented a car during that time.
However, when I tried to claim for the car rental amount in full, I was only being offered 14 days of payment, which is RM 1500, instead of the total amount of RM 3210. The reason behind is due to the adjuster report which stated that 14 days is enough for the repair.

I know that it is Bank Negara policy claim guidelines.

However, is there method for me to claim more or the full amount?
It is so unfair to be knocked by someone and not only suffer the lost of precious time and money incurred during the time. Why can't we claim for full amount?

Or is there any possibility for me to sue the car owner who knocked me?

Any lawyer familiar with the case/situation, please advice.

Many Thanks.