On a 75% roster you have a choice:
7 days consecutively off per 28 days (the "split month") with a minimum of 6 days off in the 3 weeks "on" (usually in pairs, but sometimes 3 and sometimes wrapping round the part-time week giving 8 or 9 days off)
Or the "split week" where you allocate 3 or 4 days per week to work, up to a nominal 15 per month.
You are capped at 700 hours.
And although there are some detractors (see above, but they probably haven't tried it), and although this probably equates to a "full-time" roster of say 20 years ago, you just have to deal with it - that's just the way it is. Suits me - I go away on holiday every other month.
Welcome to you all.