L went shopping in Canada and kept all my receipt can I claim all the taxes I paid in shopping?

I was in Canada last weekend, went shopping and kept all the reciepts, a worker in Canada told me that I can get refund on all the texas I paid on the merchendise I bought, is this true? if yes, how can I claim the tax refund?|||You had to claim that at the airport or the border crossing when you came back. If you're already home, it's too late.