TFG Online shopping

I ordered a pair of shoes which was delivered, one is size 3 and the other size 4, the one shoe has the security tag on it. I reported this immediately and no response was received, i called the next day and was advised that this will be attended to and feedback be given within maximum 48 hours, i did this 3 times already after the 48 hour waiting period, no one responds with feedback and i am sitting with shoes that cannot be used. The agent suggested i go to a store to return the shoes for the correct size etc. What is the purpose of online shopping if i must go to the shop to rectify this mess. The worst online shopping experience ever.