Ensure stale and causing illness

Purchased Ensure 3 cans Chocolate with manufacturing date March this year, the powder smells stale and completely off, doesnt mix either

Within 3 weeks of drinking the first can I became very sick, did not think it was Ensure that was making me sick.

I stopped using Ensure and after 2 days I am feeling much much better.

I mailed Abbot they have not bothered to respond to me at all, there is something very very wrong with this ensure