The school uniform battle continues

Forgive me if this post is off on a tangent - I just need to get it out there and off my chest.
Over the years we have had a constant battle with Cruella regarding the boys' school uniform. Basically we buy it and she keeps it, so we buy more and ... she keeps it, so we buy more - do you get the picture?
I thought we'd put an end to all that last September, when we bought double uniform for both boys and sent a set with them to Cruella's. The instructions were clear - she needed to send a full set each weekend, which we would send them to school in each Wednesday (we take them to school and she collects them on Wednesdays). We are now 4 weeks into the school term and I am almost at boiling point - I sent both boys to school today in the last whole uniform we had. When you consider they had 4 sets each and only go to school from here Monday, Tuesday and Wednesdays! So Cruella is up to her old tricks again :-
Weeks 1 - She sent no uniform at all
Week 2 - No shirts or jumpers and trousers aged 8-9 yrs that ended mid shin on both boys (I put them straight in the recycle bin)
Week 3 - Two shirts (yippee), No jumpers and trousers that fit both him and me, yes they were a little on the large side!
Week 4 - Stained shirts (off white), no jumpers and the same huge trousers I returned to her the week before!

What does a girl do? Don a balaclava and sneak into her house to steal the stuff back? No, I'm going to spend my day off shopping for school uniforms, then evening labelling them. Why? Because what else can I do?