Sounds like for whatever reason your resolved status isn't triggering the clock on your calls to be stopped, so any associated notifications (attached to any SLA's) are still being sent out as normal as if it were still ticking, such as breaches etc.
Is this a new process? Has this started happening just recently or for a while and have any process changes taken place recently?
May be worth to check your process SLA's too just to rule anything odd out there, but it does sound like the clock isn't being triggered to stop as it should.
At least that's my theory.
As well as the advice above, I think that much of the advice on this thread will be relevant to you although your scenario is a little different: