I have questions regarding billing Vestibular Balance Tests.

Our Physical Therapy Office recently started a Vestibular Balance Program and I was told to bill for the 2 tests that are being performed at the same time - CPT codes 92541 Spontaneous Nystagmus Test & 92542 Positional Nystagmus Test with recordings but then I started to receive lots of denials. I looked into the 2 CPT codes and found out that these can't be billed together because CPT code 92540 includes the 2 tests. I was told by someone from Medicare that these are not part of Physical Therapy and should not be billed with the GP modifier so I took the GP modifier out and was still denied by Medicare. Bc/Bs only paid for one and denied the other

What is the best way to bill for the 2 tests without getting denials from Medicare & Bc/Bs? Would it be better to bill just the 92540 and what do they mean by "with recording" in these CPT codes? What exactly do they record?
Would it be better to bill 92531 and 92532 without recording?