Why is it illegal for me to buy cigarettes on the internet?

i am a pensioner(senior citizen) living in the uk. is it an infringement of my human rights to stop me buying cigarettes on the internet. my well to do neighbour can fly to spain three times a year and bring back 3200 cigarettes plus tobacco each time quite legally.why is this acceptable when i can not order a few cartons to keep up my 10 a day disgusting habit.