In line with your attempts to get rid of online ads, you’ll also want to try and limit your exposure to the situations that tempt you to spend. If it's the mall, try to visit it less and not once every week. Avoid going to places that let you window shop for too long and if you find yourself spending more money when you’re with a particular friend or relative, try to schedule free or inexpensive activities with that person, like getting coffee, cooking dinner or going for a walk.
If online shopping is your choice of retail therapy, perhaps try limiting your visit to online shopping websites (even if it's just to take a peek). Try un-bookmarking them from your browser and keep track of how often you visit it. Once you realise how often you go to the websites, turn it down a notch. Also, don’t store your credit card details on online shopping websites. Instead, choose to enter your credit card and billing information each time you make a purchase. The extra time required to take your credit card out of your wallet and manually enter the information will add some mindfulness to the purchase process.