GetSecurityLevel() returns discrete values (HEStd_128_classic, HEStd_192_classic, HEStd_256_classic, HEStd_128_quantum, HEStd_192_quantum, HEStd_256_quantum, HEStd_NotSet,), not the the bit security level.
If you want to determine the bits of security for some parameters, take a look here How to determine the security level by other parameters?.