If there is someone in the office a secratary or admin aide, then you should be able to get your records, Doctors are by law bound not to leave you in the situation you are re your meds.
Keep calling, tell them all you need is your records, at the very least they should do that.
I have had doctors leave, but my doctor left me with a months supply of the meds he knew I would need. Again they should do that at the very least.