I'm a member of one of the accounting institutes and they told me the qualification was equivalent to a BA or MBA, so I went to my appointment at the time (2016) and the Council Registry Office lady had never seen the letter from the institute, called Home Office and they said either a UK degree or a test is required. So I went straight for the test (£150). Unfortunately you cannot negotiate with UKVI.... Note that the service through registry offices has been discontinued a few years back, moved to online and UKVCAS.
You can of course contact the helpline but they will recite what is published in the AN guidance:
https://www.gov.uk/government/publicati ... n-guidance. Clearly £150 is a lot of money for a 10 minute chat - I thought so at the time but just wanted to get the application in - you won't be able to talk to UKVI caseworkers or decision makers, only helpline staff who are outsourced contractors.