Sainsburys - New customer with a new email address

Hi, Just checking is it still possible to do online shopping with a new email id to get £18 offf from 60 spend. I used this vouchers last year couple of times with different email address and they cancelled my last order and received a phone call from cust service. They said they cancelled all my accounts, and said do not shop as a new customer any more. All happened in last year july. Haven't shopped online at sainsburys again. Has anyone got any experience like this?