I don't know if your doctor got the RIGHT PTH level and did he check for phosphorus too? And did he do a simple urine analysis? The right tests might prove that this indeed is 'nothing" and it sounds like your doctor isn't qualified-the next person you should see is and Endocrinologist not a kidney specialist.
I would make another appointment to discuss this with your doctor or, if he does not give you a satisfying answer, then, see another one.
High blood calcium needs further investigation to find the cause.
The far most cause is hyperparathyroidism. Now that is ruled out in your case, further testing is needed.
Some other causes are serious and some relatively harmless.
One of the "harmless" causes are excessive vitamin D intake.
Why did your doctor wait a year before taking further action?