Full of Spam & Hackers

I placed an ad with Autotrader to sell my car, since day one I have received numerous texts and phishing emails from dodgy people/companies. I've reported one to Autotrader (they already knew about it) and just now I've received another 2 emails telling me I owe £45 for the placement of an ad for my vehicle. It turns out my account was hacked, my advert was changed as were my contact details. The hacker changed my ad to include his/her contact details and reduced the car value by around £8,000. It was at this point that I cancelled my ad & asked for a full refund. Autotrader cancelled the ad & refunded my money as soon as I asked and from the conversation I had with them it appears this is very normal. Beware!