You may have just gotten lucky. It seems like the situation in the US is highly location/pharmacy-specific. The other variables are type (IR/XR, generic/non, etc.) and unit dosage. The worst hit seem to be 10mg/20mg generic IR Adderall, because that is usually the most popular and cheapest option. Switching to XR or to a less-common unit size (like 25mg) may increase the odds of finding it somewhere.
It really is a super frustrating situation. Because of the tight controls on the drug, prescriptions are almost always sent electronically from provider to pharmacy, and any changes or transfers must go through the provider. Most providers aren't going to play whack-a-mole by continuing to transfer the script, and as the article implies, changing medication type (Ritalin/Adderall/Vyvanse) or IR/XR can have significant impact on the effectiveness and potential side-effects. Responsible providers aren't just going to flip/flop medications without at least a consultation.