Energy comparison and switching site

Last weekend I received an email out of the blue welcoming me to a new electricity provider that I'd never heard of, listing my direct debit details. I immediately suspected a scam and requested them to delete all my details and let me know, with evidence. I felt quite shocked, since I have a contract that began in January. From curiosity, I asked the new company where they had got my details and I traced it back to a company called Look After My Bills, who I had registered with. I contacted them to tell them what had happened and pointed out how worried I'd been by a possible scam. I asked why they had initiated the switch without checking with me first! No satisfactory reply. Yesterday I had a letter from my current (!) supplier saying they were sorry to see me go! I have tried to explain to the switching company why this has all been so difficult for me. I just would like reassurance that others agree that I should have been warned/informed before the switch was initiated, not after. Would you have expected this? Thank you.