I've been told by AAgents that anytime you change the type of an award, there is a fee equivalent to the redeposit fee of $150. AA-only to AA-All-Partners, for example, even if both awards are at the same Saver level. I've even had them try to charge me, as a non-elite, when I tried to change an AA-All-Parnters award (a LAN+AA) to an AA-only set of flights, though other agents have told me that the AA-All-Partners award can be changed to all-AA without a penalty.

In your case you are changing award types and mileage levels. You probably could have switched from AS to AA-only without a fee, if AA had saver available. Though maybe not. But you're switching from SAAver to AAnytime, which absolutely is a different award type, and would be even if your original award was all-AA. AAdvantage and pretty much every other airline FF program treats changing award mileage levels as a redeposit (which gets the fee) and then a new award. Sorry.