Defective multivitamins

Bought brainchild multivitamins for my 8 year old daughter, from take a lot and found to be defective notified Commedhealth via email and telephone, they said they were sorry and promised to replace the product but they never did, however thinking it was only that batch was faulty I bought new one from Dis-chem and they also defective, they are melting while in the pack with everything in it to protect it from any fault it defective but still do. This is not right and not god for our children