Generic Keppra

My son was diagnosed with JME at age 18 four years ago. He was prescribed Keppra which worked well for the next 18 months.  His Keppra blood levels were constant at around 30 and seizures were controlled.  Suddenly  his Keppra blood levels started falling and he started experiencing a grand mal seizure about every 3 weeks.  His Keppra blood levels fell to 25, then 16, then 12, then 8.  Eventually his neurologist refused to treat him as he accused him of not taking his medication, although we (his parents) had monitored this closely and knew that he had never skipped a dose in 6 months.  I spoke to our pharmacist who told me that about the time he started having seizures again was when they had switched from a US-made generic to an India-made generic.  She also told me off the record that she personally would not take a drug made in India due to their poor quality control, as many drugs have a lower amount of the active ingredient than the label states or they have none at all!  She managed to special order the US made generic (TEVA) for about 6 months when his Keppra blood levels went back up to normal and no seizure activity.  Then the pharmacy management prevented her from ordering the TEVA drug due to it's cost (higher than other generics).  We managed to find another pharmacy who special ordered the TEVA brand for a few months but they, too, had to stop ordering it due to cost mandates from their home ofice.  He is now on Keppra name brand but his blood levels are down a gain and seizure activity continues.  Has anyone had a similar experience with generics and/or name brand?.  While he was on the TEVA generic his mood was better, cognitive abilities were improved and his memory was better, but I cannot find a pharmacy in Southern California who is willing to order it for us.  I have contacted the TEVA manufacturer to no avail.  Can anyone help?