In the US you should be notified when they receive the cpu, their evaluation of the cpu and the response to your claim in short order. When I rma'd my 5950x a 3rd party in Miami handled the claim and it took about a week from start to finish before I received my replacement. Your rma approval email should have pertinent info.
You should check the tracking number to the rma center on the AMD provided shipping label to see if they received it and when then contact tech support.