It sounds like your bolus is working, but remember the higher the bg the more stubon it can be coming down..
I actually do a dual correction (you need to remeber that I don't have any wizards on my spirit pump
)
I work out the correction bolus needed to return my levels to normal range, I then bolus this and depending on what the BG is I set a TBR of between 120-140% for an hour... Then check after the hour to see if I may need to set another TBR..
But most will advise with BG levels above 16mmol/l that using an insulin pen to inject the correction dose is more effective at budging them.. But if you have IOB and correction wizards etc, that these will be wrong for a period of time afterwards, as they won't take into consideration the pen injected insulin..
If you are finding that your BG's are going off near the end of 72 hours, it may well be that you are going to be a pumper who have to change there sets earlier before times up...
You might find that when you've got your sets in certain area's that this will also be necessary to change earlier than you would do in another area..
Don't get dishearted as you build your experience up it gets better.. You never know, you may have been unlucky and had a air bubble sneaky past the tubing