READ TABLE statement keeps failing

Hello Experts,

I'm having a tough time to do a simple READ TABLE statement on two tables. My two tables are ( pi_git_zrerate_dtl ) and ( lt_zrerate_output_vf ) and both have same data and fields as well which I want to compare but when READ TABLE statement always fails when in pi_git_zrerate_dtl table VBELN is same on multiple rows. I even try to pass other fields (KDMAT and POSNR) which are not same and should make a unique records but still READ fails (as shown in below screen shots).

Can anybody see what mistake I'm making in the above code and please tell me how to rectify it?

Many thanks in advance.