Sorry to hear about this.

Try for some compensation from the council - eg some plants of things that are now too late to grow from seed, and at very least reimbursement for the cost of wasted seed, fertiliser etc.

Have a look at your council's complaints procedure, and there is a Council Ombudsman as last resort if you've gone through the Council's complaints system.

Meanwhile, especially if you're down south with a longer growing season, you've still time to sow some things, eg mange-tout peas, runner beans, and all the quick crops like lettuce. And you're in great time for all the Japanese veg, which need to be sown after the longest day else they tend to bolt, and things like swiss chard.

And ask around your fellow allotmenteers - they may have the odd spare plant that they'd be happy to give you.