I think, wheel balance karnay sey pehlay aapko machine ko kuj input parameters b dainay partay hain, like rim size, aspect ratio and width of tires. Agar machine mein inn parameters ki input sai sey na ho, then b balancing k issues aa saktay hain. Then, machines also need to be calibrated after some time.
Bro you need to check wheel balancing again, preferably from some other well-reputed shop! And if you live somewhere near PWD Society / Bahria Town Phase 1-6, Rawalpindi; I can refer you to a very good shop. (Mainay last year October mein wheel balancing / alignment karwai thi, it has since been driven for 22,000 kms; dubara kabhi zarurat nai pari, although 2-3 baar apni tassalli k liay recheck b karwaya, but not even 1 gram weight got added)