It seems that Nexaph has removed GLP1s from their site altogether. Normally the test from a presale would show up in a week or two. Not sure what they are planning in that department. I wouldn't worry too much about the purity. They have a pretty good track record. The only issue you really have is overfill. The Tirz is most certainly more than just 30mg. The real question is how much more.
So what do you do at this point? Well .. if it were me I would go forward with using your purchase but would assume that your vials are at least 35mg maybe even as much as 40mg. From there I would plan a very conservative titration schedule. It is more important to avoid an overdose than it is to worry about an underdose. In a few weeks you can try contacting Nexaph to find out if there are any test results from your batch that he hasn't posted.
-- Important info. I am not a doctor. I have zero medical training other than first aid and CPR.
I am simply saying what I would do in a given situation. I am nothing but a stranger on the internet. Use your own best judgement.