personal experience - one time I served on a jury and then was resummoned within the 3 year period with which you cannot be summoned. So I called and told them and they excused me (I had proof of my previous summons). It was funny, my name came up like 2 years 8 months later, so just inside the window.

I feel like as long as you have the written notice as proof then you are going to be all good. Mistakes happen. Just follow up if you don't get that proof...