Unfortunately, this kind of scenario occurs again and again with uni group work.
First off, what is the weighting of the group presentation? Usually it's 25% of the module grade.
Normally there is a component in the assessment for the individual contribution (maybe 20%?) which allows for differentiation of marks within the group, especially when there are passengers who do nothing or very little - is that the case here?
If not, you all get the same mark which may seem harsh but what that does signify is that group dynamics & negotiating the assessment task as a group is given particular emphasis.
What are the assessment criteria, just out of interest?
Do you know for a fact that the work is going in via Turnitin? As far as I am aware, slides can't be run through it - so are you submitting a plain word processed document of all the slide content?
In terms of what you can do, you have already let your tutor know the situation and they have taken the view that it's all about group work so sort it out amongst yourselves.
You could take the "damage limitation" approach and devote a specific and limited amount of time (eg 3 hours) to tidy up the slides - not to re-do them, just to remove the most offending bits. Is there even one person in the group who could work with you on this?
You've just got to get through this with the least extra work as you can, then put it behind you