Never experienced it myself (with my site/business) but i have observed it a little. My (humble) suggestion: Your product/service/business is likely to thrive

Never experienced it myself (with my site/business) but i have observed it a little. My (humble) suggestion: Your product/service/business is likely to thrive (you've already said your T&C has 'evolved' since their copy) and given the ever-changing properties of this tech sphere - change rapidly! Design/aesthetics/marketing material and the like are great, but it's your customer service that's going to keep business - so focus on that. If you update your site design and it’s copied again, dont worry. Like you said: it must be good right? The value you offer to your customers is you - your service, your passion and your values. That can’t really be copied - well, not effectively. Focus on the things that matter. Sure it might hurt to be stolen from, but rise above. Your customers will notice.