Infacare number 3

Infacare number 3 - I have twins who are currently on Infacare number 3. I usually buy 4 boxes on payday and then refills as and when i need it. The 4 boxes i have bought recently seem either to be off or expired or seriously something wrong with them, even though the expiry date is not past. The reason why i say this is because within 2 hours of making the bottles, it is off like proper milk when it is sore. I cannot afford to buy 4 more pack as i am a single mom and i think that Aspen needs to be aware of this.