*****ulent Transactions

My Takealot experiences are mixed. Usually get the things I ordered in good condition and timeously. My problem is that, regularly, subsequent to ordering from Takealot, I get an sms from my bank saying that they suspect a *****ulent transaction on my bank card from Takealot. The amount shown is not an amount that I have transacted. I tried several times to contact Takealot without success to report this.